Fresh Crater on Mars Spied by NASA Spacecraft

A NASA Mars probe has photographed an impact crater that was blasted out of the Red Planet in just the last few years.

The HiRISE camera aboard NASA's Mars Reconnaissance Orbiter (MRO) captured the crater, which lies in the Red Planet's equatorial Elysium Planitia region, on Dec. 2, 2014. Scientists say the impact that gouged out the hole must have occurred between February 2012 and June 2014, based on previous images of the area.

The crater is about 40 feet (12 meters) wide, said HiRISE team member Ingrid Daubar of NASA's Jet Propulsion Laboratory in Pasadena, California.

"We've been finding new craters like this for a few years now, and from studying their frequency, we've come up with a cratering rate for Mars based on them," Daubar told Space.com via email.

"For craters this size (12 m diameter), we expect about 30 of these are forming over all of Mars each year," she added. "We only find a few of them, though, because we have to be looking in the right area. They're not as easy to find over non-dusty areas where they don't form these huge dark blast zones around the impact site."

The new photo is the first one HiRISE — short for High Resolution Imaging Science Experiment — has taken of the crater. The feature was actually discovered by MRO's Mars Context Camera, NASA officials said.

The objects that create Martian craters such as this one strike the surface at very high speeds — an average of 22,000 mph (35,400 km/h) — and are almost always completely destroyed in the process, Daubar said.

Indeed, there is no sign of the impactor in the new HiRISE photo. The silvery crescent toward the right side of the crater is just the illuminated interior wall of the crater, Daubar said. (In the image, sunlight is coming from the lower left.)

The $720 million MRO mission launched in August 2005 and arrived in orbit around Mars in March 2006. The spacecraft has been studying the Red Planet ever since with six scientific instruments. MRO also serves as a vital communications link between Earth and NASA's active Mars surface craft, the Opportunity and Curiosity rovers.

Retro NASA Travel Posters Invite You to Real Alien Worlds

These amazingly retro NASA travel posters feature three real-life alien planets: Kepler 186f, HD 40307g and Kepler 16b. They were created for NASA's PlanetQuest project at the agency's Jet Propulsion Laboratory in Pasadena, California to share facts about the strange new worlds with the public.

Opportunity Rover Snaps Mars Panorama from Crater Rim

The Opportunity rover took the photo on Tuesday (Jan. 6) from atop "Cape Tribulation," on the western rim of Endeavour Crater. The summit sits about 440 feet (135 meters) above the surrounding plains — higher than any other point Opportunity has reached since arriving at Endeavour's rim in August 2011, NASA officials said

Researchers in remote East Antarctica think a massive area of fractured ice discovered last month could be a newfound meteorite impact crater.

The mile-wide crater (about 2 kilometers across) is a circular scar marked by fractured, rumpled ice — a striking blot in this otherwise smooth section of Antarctica's King Baudouin Ice Shelf. It was spotted by German scientist Christian Müller during an aerial survey by plane on Dec. 20, 2014.

"I looked out of the window, and I saw an unusual structure on the surface of the ice," Müller said in a video describing the discovery. "There was some broken ice looking like icebergs, which is very unusual on a normally flat ice shelf, surrounded by a large, wing-shaped, circular structure," said Müller, a geoscientist with Fielax, a private company assisting Antarctic research.

Lucky find

The possible impact crater is about twice the size of Arizona's Barringer Meteor Crater. Satellite images suggest the broken-up ice could be at least 25 years old.

The crater was a serendipitous find, sighted by chance north of Belgium's Princess Elisabeth Research Station. German researchers at the station intended to remotely survey the surrounding bedrock, in order to gather new details on the Gondwana supercontinent's formation and breakup between 550 million and 180 million years ago. Flying over busted-up ice shelves — the floating extensions of the Antarctic Ice Sheet — was not part of the research plan.

"We were only flying that far in the north because the radar equipment had broken, and we didn't want to waste a good flying day," said Graeme Eagles, a scientist at Germany's Alfred Wegener Institute who is currently leading the geophysical research survey. "It's been a tremendously exciting couple of weeks," he added. "It really is a very raw form of science, with a lot of people speculating on what might or might not be the cause."
Antarctic researchers

At first, Müller connected the crater to a 2004 meteor blast detected above this part of East Antarctica. Recently, however, the German research team discovered the crater in satellite images dating back to 1996, Eagles said. "The [connection] to the 2004 event really piqued our interest in the first place, but I don't think what we've seen in the satellite images rules out the possibility of an impact origin," Eagles told Live Science. "It just fuzzies the story a little bit."

Extraordinary claims

If a space rock did crash-land on the ice shelf, the meteorite was likely relatively large. Indeed, the crater's sheer size warrants skepticism, experts said. [Crash! 10 Biggest Impact Craters on Earth]

As a rule of thumb, an object that formed a crater is usually about 10 to 20 times smaller than the crater itself, said Peter Brown, director of the Center for Planetary Science and Exploration at the University of Western Ontario in Canada. That means a 1.2-mile (2 km) crater would result from an object that measures roughly 325 feet (100 meters) across, Brown said.

"A very large explosion would have caused a 2-kilometer-wide crater — much larger than anything detected impacting Earth in recent history," Brown said. "So the feature seen is almost certainly not due to any meteorite impact."

Meteorite hunter Peter Jenniskens also found the crater idea implausible. "I don't think this is an impact crater," said Jenniskens, who holds dual affiliations at the SETI Institute and at NASA's Ames Research Center, both in California.

However, Eagles hinted that the German researchers have not shown all their cards. The scientists collected photos, video and data on a Dec. 26 trip to the crater site. The team mapped the ice surface in great detail with a laser-scanning instrument that records precise changes in topography. They also surveyed the area with a radar instrument that penetrates the upper surface of the ice and snow. A number of smaller circular and subcircular structures were spotted nearby on this trip. The researchers haven't yet analyzed the data, but they hope to publish their results in a scientific journal if the structure is indeed an impact crater, Eagles said.

"This thing is very unusual indeed," Eagles said. "Extraordinary claims require extraordinary evidence, and in this case, as far as we can tell, is does look like it is extraordinary evidence."

Rock hunters

The researchers now must complete their Gondwana study before squeezing in any more trips to the crater, Eagles said. For instance, the team would like to eventually hunt for meteorites around the site.

Antarctica's cold, dry conditions preserve meteorites that weather away on other continents, and more than 20,000 space rocks have been discovered in targeted searches on the frozen surface.

While scientists do come to Antarctica specifically to hunt for meteorites, finding a potential impact crater was an unexpected thrill for everyone at the research station, the researchers said. "There are new and exciting things to be discovered at any moment, anytime, in Antarctica, and you don't have to send probes to land on comets to make people's eyes sparkle," Eagles said.

NASA's Kepler Marks 1,000th Exoplanet Discovery, Uncovers More Small Worlds in Habitable Zones

How many stars like our sun host planets like our Earth? NASA's Kepler Space Telescope continuously monitored more than 150,000 stars beyond our solar system, and to date has offered scientists an assortment of more than 4,000 candidate planets for further study -- the 1,000th of which was recently verified.
Using Kepler data, scientists reached this millenary milestone after validating that eight more candidates spotted by the planet-hunting telescope are, in fact, planets. The Kepler team also has added another 554 candidates to the roll of potential planets, six of which are near-Earth-size and orbit in the habitable zone of stars similar to our sun.
Three of the newly-validated planets are located in their distant suns' habitable zone, the range of distances from the host star where liquid water might exist on the surface of an orbiting planet. Of the three, two are likely made of rock, like Earth.
"Each result from the planet-hunting Kepler mission's treasure trove of data takes us another step closer to answering the question of whether we are alone in the universe," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate at the agency's headquarters in Washington. "The Kepler team and its science community continue to produce impressive results with the data from this venerable explorer."
To determine whether a planet is made of rock, water or gas, scientists must know its size and mass. When its mass can't be directly determined, scientists can infer what the planet is made of based on its size.
Two of the newly validated planets, Kepler-438b and Kepler-442b, are less than 1.5 times the diameter of Earth. Kepler-438b, 475 light-years away, is 12 percent bigger than Earth and orbits its star once every 35.2 days. Kepler-442b, 1,100 light-years away, is 33 percent bigger than Earth and orbits its star once every 112 days.
Both Kepler-438b and Kepler-442b orbit stars smaller and cooler than our sun, making the habitable zone closer to their parent star, in the direction of the constellation Lyra. The research paper reporting this finding has been accepted for publication in The Astrophysical Journal.
"With each new discovery of these small, possibly rocky worlds, our confidence strengthens in the determination of the true frequency of planets like Earth," said co-author Doug Caldwell, SETI Institute Kepler scientist at NASA's Ames Research Center at Moffett Field, California. "The day is on the horizon when we'll know how common temperate, rocky planets like Earth are."
With the detection of 554 more planet candidates from Kepler observations conducted May 2009 to April 2013, the Kepler team has raised the candidate count to 4,175. Eight of these new candidates are between one to two times the size of Earth, and orbit in their sun's habitable zone. Of these eight, six orbit stars that are similar to our sun in size and temperature. All candidates require follow-up observations and analysis to verify they are actual planets.
"Kepler collected data for four years -- long enough that we can now tease out the Earth-size candidates in one Earth-year orbits," said Fergal Mullally, SETI Institute Kepler scientist at Ames who led the analysis of a new candidate catalog. "We're closer than we've ever been to finding Earth twins around other sun-like stars. These are the planets we're looking for."
These findings also have been submitted for publication in The Astrophysical Journal Supplement.
Work is underway to translate these recent discoveries into estimates of how often rocky planets appear in the habitable zones of stars like our sun, a key step toward NASA's goal of understanding our place in the universe.
Scientists also are working on the next catalog release of Kepler's four-year data set. The analysis will include the final month of data collected by the mission and also will be conducted using sophisticated software that is more sensitive to the tiny telltale signatures of small Earth-size planets than software used in the past.

Alien Oceans May Flow on 'Super-Earth' Planets

 SEATTLE — Alien worlds more massive than Earth could harbor long-lasting oceans, according to new research.

Scientists have used computer modeling to show that so-called "super-Earth" planets — worlds that are up to five times more massive than Earth — can play host to long-lived oceans. The modeling shows that the oceans can potentially remain on the planet for billions of years, possibly allowing life to develop on the alien planet. Researchers presented the new super-Earth findings during a news conference at the 225th meeting of the American Astronomical Society here in Seattle.

"When people consider whether a planet is in the habitable zone, they think about its distance from the star and its temperature," lead author of the super-Earth study Laura Schaefer of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts said in a statement. "However, they should also think about oceans, and look at super-Earths to find a good sailing or surfing destination."

Scientists think that Earth's oceans have existed for almost the entire history of the planet, and water is key to life as humanity understands it. Therefore, finding other worlds with long-lived oceans could help scientists narrow down planets that might have a good chance of hosting life.

Earth's oceans are recycled. Water from the planet's oceans is pulled into the mantle from the crust due to geological activity, but water is also released from the mantle and back into the surface oceans through volcanic activity. The new computer model produced by Schaefer and her team was designed to test if this water recycling can occur on super-Earths with plate tectonics as well, according to the CfA.

In fact, some planets larger than Earth could be even better at maintaining oceans than this planet. Schaefer's model shows that a planet two to four times the mass of Earth could host oceans continuously for 10 billion years. The largest planet in the study, which was about five times more massive than Earth, didn't develop an ocean in the computer model for about 1 billion years, but those planets' oceans, once formed, continue to persist on the surface for a long amount of time. .

Schaefer and her team suggest that it might be better to hunt for life on older super-Earths. Researchers might have a better chance of finding complex life on planets that are 1 billion years older than Earth, the team said.

"It takes time to develop the chemical processes for life on a global scale, and time for life to change a planet's atmosphere," the CfA's Dimitar Sasselov, a co-author on the study, said in a statement. "So, it takes time for life to become detectable."

Planets with Odd, Mercury-Like Orbits Could Host Life

Mercury has an oddball orbit — it takes longer for it to rotate on its axis and complete a day than it takes to orbit the sun and complete a year. Now, researchers suggest photosynthesis could take place on an alien planet with a similarly bizarre orbit, potentially helping support complex life.
However, the scientists noted that the threat of prolonged periods of darkness and cold on these planets would present significant challenges to alien life, and could even potentially freeze their atmospheres. They detailed their findings in the International Journal of Astrobiology.
Astronomers have discovered more than 1,700 alien planets in the past two decades, raising the hope that at least some might be home to extraterrestrial life. Scientists mostly focus the search for alien life on exoplanets in the habitable zones of stars. These are regions where worlds would be warm enough to have liquid water on their surfaces, a potential boon to life.

Although many exoplanets are potentially habitable, they may differ from Earth significantly in one or more ways. For instance, habitable planets around dim red dwarf stars orbit much closer than Earth does to the sun, sometimes even closer than Mercury's distance.
Red dwarfs are of interest as possible habitats for life because they are the most common stars in the universe — if life can exist around red dwarfs, then life might be very common across the cosmos. Recent findings from NASA's Kepler Space Observatory suggest that at least half of all red dwarfs host rocky planets that are one-half to four times the mass of Earth.
Since a planet in the habitable zone of a red dwarf orbits very near its star, it experiences much stronger gravitational tidal forces than Earth does from the sun, which slows the rate at which those worlds spin. The most likely result of this slowdown is that the planet enters what is technically called a 1:1 spin orbit resonance, completing one rotation on its axis every time it completes one orbit around its star.

This rate of rotation means that one side of that planet will always face toward its star, while the other side will permanently face away, just as the moon always shows the same side to Earth. One recent study suggests that such "tidally locked" planets may develop strange lobster-shaped oceans basking in the warmth of their stars on their daysides, while the nightsides of such worlds are mostly covered in an icy shell.

However, if a habitable red dwarf planet has a very eccentric orbit — that is, oval-shaped — it could develop what is called a 3:2 spin orbit resonance, meaning that it rotates three times for every two orbits around its star. Mercury has such an unusual orbit, which can lead to strange phenomena. For instance, at certain times on Mercury, an observer could see the sun rise about halfway and then reverse its course and set, all during the course of one mercurial day. Mercury itself is not habitable, since it lacks an atmosphere and experiences temperatures ranging from 212 to 1,292 degrees Fahrenheit (100 to 700 degrees Celsius).

“If the sun were less intense, Mercury would be within the habitable zone, and therefore life would have to adapt to strange light cycles," said lead study author Sarah Brown, an astrobiologist at the United Kingdom Center for Astrobiology in Edinburgh, Scotland.
Light is crucial for photosynthesis, the process by which plants and other photosynthetic organisms use the sun's rays to create energy-rich molecules such as sugars. Most life on Earth currently depends on photosynthesis or its byproducts in one way or the other, and while primitive life can exist without photosynthesis, it may be necessary for more complex multicellular organisms to emerge because the main source for oxygen on Earth comes from photosynthetic life, and oxygen is thought to be necessary for multicellular life to arise.
To see what photosynthetic life might exist on a habitable red dwarf planet with an orbit similar to Mercury's, scientists calculated the amount of light that reached all points on its surface. Their model involved a planet the same mass and diameter as the Earth with a similar atmosphere and amount of water on its surface. The red dwarf star was 30 percent the sun's mass and 1 percent as luminous, giving it a temperature of about 5,840 degrees Fahrenheit (3,225 degrees Celsius) and a habitable zone extending from 10 to 20 percent of an astronomical unit (AU) from the star. (One AU is the average distance between Earth and the sun.)
The scientists found that the amount of light the surface of these planets received concentrated on certain bright spots. Surprisingly, the amount of light these planets receive does not just vary over latitude as it does on Earth, where more light reaches equatorial regions than polar regions, but also varies over longitude. Were photosynthetic life to exist on worlds with these types of orbits, "one would expect to find niches that depend on longitude and latitude, rather than just latitude," said study co-author Alexander Mead, a cosmologist at the Royal Observatory, Edinburgh, in Scotland.
The research team found these planets could experience nights that last for months. This could pose major problems for photosynthetic life, which depends on light. Still, the scientists noted that many plants can store enough energy to last through 180 days of darkness. Moreover, some photosynthetic microbes spend up to decades dormant in the dark, while others are mixotrophic, which means they can survive on photosynthesis when light is abundant and switch to devouring food when light is absent.

Another problem these long spans of darkness pose for life is the cold, which could freeze the atmospheres of these planets. Still, the investigators note that heat can flow from the dayside of such a planet to its nightside and prevent this freezing if that planet's atmosphere is sufficiently dense and can trap infrared light from the planet's star. This heat flow could lead to very strong winds, but this does not necessarily make the world uninhabitable, they added. [The Strangest Alien Planets]
"Life having to cope with such tidally driven resonances could be common in the universe," Mead said. "It changes one's perception of what habitable planets in the universe would be like. There are many possibilities that are very un-Earth-like."

However, the researchers noted that the strength of a world's magnetic field depends in large part on how quickly it spins, which suggests that planets with orbits like Mercury's might have relatively weak magnetic fields. This could mean these worlds are not as good at deflecting harmful electrically charged particles streaming from their red dwarfs and other stars that can damage organisms and strip off the atmospheres of these planets.

The investigators suggested that dense atmospheres could help keep such planets habitable in the face of radiation from space. They added that life might be confined to certain spots on the surfaces of those planets that experience relatively safe levels of radiation.
Are astronomers capable of detecting habitable planets with a 3:2 spin orbit resonance?
"Measuring the day length of extrasolar planets is enormously difficult, and the first day length measurements for any extrasolar planets were only published this year," Mead said. "Such a measurement for the planets we discuss would be much more difficult due to the fact that they are small, rocky planets around faint stars. This means that we are probably a long way from measuring the spin rates of such habitable worlds."

The Biggest Alien Planet Discoveries of 2014

This past year was a banner one for the field of exoplanet science, with the tally of known alien worlds doubling to nearly 2,000 by the end of 2014.

Here's a look at the top exoplanet discoveries of 2014, from the first potentially habitable Earth-size world to a staggering haul of 715 newly announced alien planets:

'Earth's cousin'

In April, scientists announced the discovery of Kepler-186f, the first known Earth-size planet that resides in its star's "habitable zone" — the range of distances that could support the existence of liquid water on a world's surface. [10 Exoplanets That Could Host Alien Life]

As its name suggests, Kepler-186f was found by NASA's prolific Kepler space telescope. The planet lies 490 light-years from Earth and is just 10 percent wider than our home world. Kepler-186f is not the elusive "Earth twin" that astronomers have long sought; the planet circles a red dwarf, a star smaller and dimmer than the sun. But Kepler-186f is a member of the family nonetheless, with its discoverers characterizing it as an "Earth cousin."

A habitable world next door?

Kepler-186f isn't the only planet found last year that might be capable of supporting life. A world called Gliese 832c is also potentially habitable — and it lies just 16 light-years away, a mere stone's throw considering the vast scale of the universe.

Astronomers found Gliese 832c, which also orbits a red dwarf, using three different ground-based instruments. The exoplanet is a "super Earth" at least five times as massive as Earth, its discoverers say. While Gliese 832c may be habitable, it could also resemble scorching-hot Venus, whose thick atmosphere has led to a runaway greenhouse effect.
Artist's concept of the potentially habitable super Earth Gliese 832c, against a background of a stellar nebula.

715 newfound exoplanets

Exoplanet discoveries usually come in drips and drops, but in February, the Kepler team unleashed a torrent: Researchers announced the spacecraft had spotted 715 new alien worlds, nearly doubling the known population in one fell swoop.

More than 90 percent of the newfound planets are smaller than Neptune, and four of them are habitable-zone worlds less than 2.5 times the size of Earth, scientists said.

Researchers confirmed this huge haul of Kepler planets using a technique called "validation by multiplicity," which relies on probability and statistics rather than additional observations by other telescopes.

'The Godzilla of Earths'

Another headliner from 2014 is Kepler-10c, a planet about 17 times more massive than Earth. Such hefty worlds were thought to be primarily gaseous, but Kepler-10c is rocky.

Kepler-10c is therefore the first known member of a new class of exoplanets, the "mega-Earths." This "Godzilla of Earths," as one of its discoverers described Kepler-10c, orbits a sunlike star that lies about 560 light-years from Earth.

Gas dwarfs

Just as rocky planets can apparently be much larger than previously thought, gaseous worlds can be surprisingly small. That's the conclusion of another 2014 study, which laid out the classification of "gas dwarf" exoplanets.

After studying more than 600 newfound Kepler planets, the researchers determined that worlds less than 1.7 times the size of Earth are likely to be rocky, while those at least 3.9 times bigger than our planet are gaseous. Most worlds between these two extremes are probably "gas dwarfs," planets with rocky cores and thick hydrogen-helium atmospheres that never grew to the size of Saturn, Jupiter and other gas giants, the study found.

The first exomoon?

Astronomers may have detected the moon of an alien planet for the first time in 2014, but we'll never know for sure.

The team used a technique called gravitational microlensing, which notes how a foreground object's gravity warps the light from a distant star when it passes in front of the star from Earth's perspective. The researchers saw one lensing event caused by a foreground object that could be one of two things: a free-flying "rogue planet" with a rocky exomoon, or a small star that hosts a planet about 18 times more massive than Earth.

Unfortunately, there's no way to follow up on the find, because microlensing events are random encounters. So the search for the first confirmed exomoon continues.

The first exoplanet of Kepler's new mission

Kepler's original exoplanet hunt ground to a halt in May 2013, when the second of its four orientation-maintaining reaction wheels failed. But the Kepler team devised a way to stabilize the observatory using sunlight pressure, and in May 2014, NASA approved a new, two-year mission for the spacecraft called K2, during which it has been hunting for alien planets, supernova explosions and other cosmic phenomena.

The first K2 exoplanet is now in the books. In December, researchers announced that Kepler had discovered a world called HIP 116454b, which is about 2.5 times bigger than Earth and lies 160 light-years away.

However successful K2 turns out to be, the new mission won't approach the exoplanet tally Kepler racked up during its pre-glitch operations. Kepler's original mission netted nearly 4,200 planet candidates, nearly 1,000 of which have been confirmed to date. Kepler scientists expect about 90 percent of the candidates will turn out to be bona fide planets.

The oldest potentially habitable alien planet

Also this year, astronomers announced the discovery of Kapteyn b, a super Earth that orbits in the habitable zone of a red dwarf located just 13 light-years away from our solar system.

Kapteyn b is 11.5 billion years old, making it the most ancient known planet that may be capable of supporting life. To put that age into perspective: Earth is less than 4.6 billion years old, while the universe itself was born 13.8 billion years ago. So if life took root early in Kapteyn b's history, it has had a very long time to evolve.
Artist's concept of the potentially habitable world Kapteyn b with the globular cluster Omega Centauri in the background. Kapteyn b lies just 13 light-years from Earth.

Planets around every star?

Another 2014 study suggests that virtually every red dwarf in the Milky Way galaxy hosts at least one planet — and that at least 25 percent of these small, dim stars in the sun's own neighborhood host habitable-zone worlds.

That translates to a lot of life-friendly real estate; red dwarfs make up at least 70 percent of the galaxy's 100 billion or so stars.

The team arrived at these conclusions after analyzing observations made by two instruments in Chile — the High Accuracy Radial velocity Planet Searcher (HARPS) and the Ultraviolet and Visual Echelle Spectrograph (UVES). The results bolster previous findings made by researchers who looked at Kepler data, indicating that the Milky Way is teeming with billions of planets.

Earth-like worlds in two-star systems?

This year, for the first time, astronomers found a rocky planet in an Earth-like orbit around a single star in a two-star system.

The world, known as OGLE-2013-BLG-0341LBb, lies about 3,000 light-years from Earth and is likely too cold to support life as we know it (it circles a red dwarf). And it's not the first planet to be spotted in a two-star system, or the first one known to circle just one of a binary's two stars.

But the discovery of OGLE-2013-BLG-0341LBb is significant, showing that rocky planets can form relatively far from their host stars even in two-star systems, researchers said. (Previously, it was thought that a nearby companion star might disrupt the planet-forming disk too much for this to occur.) Its existence suggests that habitable planets may be more common than scientists had supposed; half of all Milky Way stars exist in binary systems.

Mars Has 'Macroweather,' Just Like Earth

Mars, like Earth, experiences "macroweather" — atmospheric effects that lie in between short-term weather and long-term climate, researchers say.

The discovery might not only shed light on how Earth's atmosphere behaves but could also yield insights on all planets and moons with atmospheres, scientists added.

Weather on Earth changes on a daily basis due to constant fluctuations in the atmosphere, while climate varies over decades. In the past 30 years, researchers have started to understand that Earth's atmosphere also experiences something between these two extremes called "macroweather," said lead study author Shaun Lovejoy, a nonlinear geophysicist at McGill University in Montreal.
To see if other worlds might have macroweather, Lovejoy and his colleagues investigated Mars because its atmosphere is relatively well studied. They analyzed data collected by NASA's Viking 1 and 2 missions, which made measurements on the Martian surface from the mid-1970s through the early 1980s, as well as data collected from orbit by NASA's Mars Global Surveyor spacecraft.

By accounting for how the sun heats the Red Planet, as well as the thickness of the Martian atmosphere, the study team discovered that macroweather exists on Mars, although its time scale is shorter than on Earth. On Mars, the shift from weather to macroweather takes place over 1.8 Martian sols, equivalent to about two Earth days, while that transition takes a week to 10 days on Earth.

These differences mostly have to do with how Earth and Mars differ in size and how much sunlight they receive, researchers said. Mars is only slightly more than half as wide as Earth, about one-tenth of Earth's mass and orbits about 50 percent farther away from the sun than our home planet does.

The findings also revealed that weather on Mars can be predicted only two days in advance, compared to 10 days on Earth. This could "prove tricky for the European lander and rover," study co-author Jan-Peter Muller, of University College London, said in a statement, referring to the ExoMars mission, which aims to launch an orbiter toward the Red Planet in 2016 and a Mars rover in 2018.

Lovejoy and his colleagues are currently working on a global macroweather model that may be capable of making forecasts much better than current climate models at the range of months to decades, he told Space.com.

Such research could help scientists increase their knowledge of the weather on Venus, Saturn's moon Titan, potentially the gas giants Jupiter, Saturn, Uranus and Neptune, and exoplanets and exomoons orbiting distant stars.

The scientists detailed their findings online Nov. 13 in the journal Geophysical Research Letters.

NASA Rover Finds Active and Ancient Organic Chemistry on Mars

NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill.
"This temporary increase in methane -- sharply up and then back down -- tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, a member of the Curiosity rover science team. "There are many possible sources, biological or non-biological, such as interaction of water and rock."
Researchers used Curiosity's onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion. Before and after that, readings averaged only one-tenth that level.
Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed Cumberland, the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.
Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life. Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.
"We will keep working on the puzzles these findings present," said John Grotzinger, Curiosity project scientist of the California Institute of Technology in Pasadena. "Can we learn more about the active chemistry causing such fluctuations in the amount of methane in the atmosphere? Can we choose rock targets where identifiable organics have been preserved?"
Researchers worked many months to determine whether any of the organic material detected in the Cumberland sample was truly Martian. Curiosity's SAM lab detected in several samples some organic carbon compounds that were, in fact, transported from Earth inside the rover. However, extensive testing and analysis yielded confidence in the detection of Martian organics.
Identifying which specific Martian organics are in the rock is complicated by the presence of perchlorate minerals in Martian rocks and soils. When heated inside SAM, the perchlorates alter the structures of the organic compounds, so the identities of the Martian organics in the rock remain uncertain.
"This first confirmation of organic carbon in a rock on Mars holds much promise," said Curiosity Participating Scientist Roger Summons of the Massachusetts Institute of Technology in Cambridge. "Organics are important because they can tell us about the chemical pathways by which they were formed and preserved. In turn, this is informative about Earth-Mars differences and whether or not particular environments represented by Gale Crater sedimentary rocks were more or less favorable for accumulation of organic materials. The challenge now is to find other rocks on Mount Sharp that might have different and more extensive inventories of organic compounds."
Researchers also reported that Curiosity's taste of Martian water, bound into lakebed minerals in the Cumberland rock more than three billion years ago, indicates the planet lost much of its water before that lakebed formed and continued to lose large amounts after.
SAM analyzed hydrogen isotopes from water molecules that had been locked inside a rock sample for billions of years and were freed when SAM heated it, yielding information about the history of Martian water. The ratio of a heavier hydrogen isotope, deuterium, to the most common hydrogen isotope can provide a signature for comparison across different stages of a planet's history.
"It's really interesting that our measurements from Curiosity of gases extracted from ancient rocks can tell us about loss of water from Mars," said Paul Mahaffy, SAM principal investigator of NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of a report published online this week by the journal Science
The ratio of deuterium to hydrogen has changed because the lighter hydrogen escapes from the upper atmosphere of Mars much more readily than heavier deuterium. In order to go back in time and see how the deuterium-to-hydrogen ratio in Martian water changed over time, researchers can look at the ratio in water in the current atmosphere and water trapped in rocks at different times in the planet's history.
Martian meteorites found on Earth also provide some information, but this record has gaps. No known Martian meteorites are even close to the same age as the rock studied on Mars, which formed about 3.9 billion to 4.6 billion years ago, according to Curiosity's measurements.
The ratio that Curiosity found in the Cumberland sample is about one-half the ratio in water vapor in today's Martian atmosphere, suggesting much of the planet's water loss occurred since that rock formed. However, the measured ratio is about three times higher than the ratio in the original water supply of Mars, based on the assumption that supply had a ratio similar to that measured in Earth's oceans. This suggests much of Mars' original water was lost before the rock formed.
Curiosity is one element of NASA's ongoing Mars research and preparation for a human mission to Mars in the 2030s. Caltech manages the Jet Propulsion Laboratory in Pasadena, California, and JPL manages Curiosity rover science investigations for NASA's Science Mission Directorate in Washington. The SAM investigation is led by Paul Mahaffy of Goddard. Two SAM instruments key in these discoveries are the Quadrupole Mass Spectrometer, developed at Goddard, and the Tunable Laser Spectrometer, developed at JPL.
The results of the Curiosity rover investigation into methane detection and the Martian organics in an ancient rock were discussed at a news briefing Tuesday at the American Geophysical Union's convention in San Francisco. The methane results are described in a paper published online this week in the journal Science by NASA scientist Chris Webster of JPL, and co-authors

NASA Voyager: 'Tsunami Wave' Still Flies Through Interstellar Space

• The Voyager 1 spacecraft has experienced three shock waves
• The most recent shock wave, first observed in February 2014, still appears to be going on
• One wave, previously reported, helped researchers determine that Voyager 1 had entered interstellar space
The "tsunami wave" that NASA's Voyager 1 spacecraft began experiencing earlier this year is still propagating outward, according to new results. It is the longest-lasting shock wave that researchers have seen in interstellar space.
"Most people would have thought the interstellar medium would have been smooth and quiet. But these shock waves seem to be more common than we thought," said Don Gurnett, professor of physics at the University of Iowa in Iowa City. Gurnett presented the new data Monday, Dec. 15 at the American Geophysical Union meeting in San Francisco.
A "tsunami wave" occurs when the sun emits a coronal mass ejection, throwing out a magnetic cloud of plasma from its surface. This generates a wave of pressure. When the wave runs into the interstellar plasma -- the charged particles found in the space between the stars -- a shock wave results that perturbs the plasma.
"The tsunami causes the ionized gas that is out there to resonate -- "sing" or vibrate like a bell," said Ed Stone, project scientist for the Voyager mission based at California Institute of Technology in Pasadena.

https://www.youtube.com/watch?feature=player_embedded&v=_u-RZTwpECg&x-yt-ts=1421914688&x-yt-cl=84503534

This is the third shock wave that Voyager 1 has experienced. The first event was in October to November of 2012, and the second wave in April to May of 2013 revealed an even higher plasma density. Voyager 1 detected the most recent event in February, and it is still going on as of November data. The spacecraft has moved outward 250 million miles (400 million kilometers) during the third event.
"This remarkable event raises questions that will stimulate new studies of the nature of shocks in the interstellar medium," said Leonard Burlaga, astrophysicist emeritus at NASA Goddard Spaceflight Center in Greenbelt, Maryland, who analyzed the magnetic field data that were key to these results.
It is unclear to researchers what the unusual longevity of this particular wave may mean. They are also uncertain as to how fast the wave is moving or how broad a region it covers.
The second tsunami wave helped researchers determine in 2013 that Voyager 1 had left the heliosphere, the bubble created by the solar wind encompassing the sun and the planets in our solar system. Denser plasma "rings" at a higher frequency, and the medium that Voyager flew through, was 40 times denser than what had been previously measured. This was key to the conclusion that Voyager had entered a frontier where no spacecraft had gone before: interstellar space.
"The density of the plasma is higher the farther Voyager goes," Stone said. "Is that because the interstellar medium is denser as Voyager moves away from the heliosphere, or is it from the shock wave itself? We don't know yet."
Gurnett, principal investigator of the plasma wave instrument on Voyager, expects that such shock waves propagate far out into space, perhaps even to twice the distance between the sun and where the spacecraft is right now.
Voyager 1 and its twin, Voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft and is expected to enter interstellar space in a few years.
JPL, a division of Caltech, built the twin Voyager spacecraft and operates them for the Heliophysics Division within NASA's Science Mission Directorate in Washington

Rosetta Instrument Reignites Debate on Earth's Oceans

The question about the origin of oceans on Earth is one of the most important questions with respect to the formation of our planet and the origin of life. The most popular theory is that water was brought by impacts of comets and asteroids. Data from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument aboard the European Space Agency's Rosetta spacecraft indicate that terrestrial water did not come from comets like 67P/Churyumov-Gerasimenko. The findings were published today in the journal Science.
Researchers agree that water must have been delivered to Earth by small bodies at a later stage of the planet's evolution. It is, however, not clear which family of small bodies is responsible. There are three possibilities: asteroid-like small bodies from the region of Jupiter; Oort cloud comets formed inside of Neptune's orbit; and Kuiper Belt comets formed outside of Neptune's orbit.
The key to determining where the water originated is in its isotopic "flavor." That is, by measuring the level of deuterium - a heavier form of hydrogen. By comparing the ratio of deuterium to hydrogen in different objects, scientists can identify where in the solar system that object originated. And by comparing the D/H ratio, in Earth's oceans with that in other bodies, scientists can aim to identify the origin of our water.
The ROSINA instrument on the Rosetta spacecraft has found that the composition of comet 67P/Churyumov-Gerasimenko's water vapor is significantly different from that found on Earth.
The value for the D/H ratio on the comet is more than three times the terrestrial value. This is among the highest-ever-measured values in the solar system. That means it is very unlikely that comets like 67P/Churyumov-Gerasimenko are responsible for the terrestrial water.
The D/H ratio is the ratio of a heavier hydrogen isotope, called deuterium, to the most common hydrogen isotope. It can provide a signature for comparison across different stages of a planet's history.
"We knew that Rosetta's in situ analysis of this comet was always going to throw us surprises," said Matt Taylor, Rosetta's project scientist from the European Space Research and Technology Center, Noordwijk, the Netherlands. "The bigger picture of solar-system science, and this outstanding observation, certainly fuel the debate as to where Earth got its water."
Almost 30 years ago (1986) the mass spectrometers on board the European Giotto mission to comet Halley could, for the first time, determine D/H ratio in a comet. It turned out to be twice the terrestrial ratio. The conclusion at that time was that Oort cloud comets, of which Halley is a member, cannot be the responsible reservoir for our water. Several other Oort cloud comets were measured in the next 20 years, all displaying very similar D/H values compared to Halley. Subsequently, models that had comets as the origin of the terrestrial water became less popular.
This changed when, thanks to the European Space Agency's Herschel spacecraft, the D/H ratio was determined in comet Hartley 2, which is believed to be a Kuiper Belt comet. The D/H ratio found was very close to our terrestrial value -- which was not really expected. Most models on the early solar system claim that Kuiper Belt comets should have an even higher D/H ratio than Oort cloud comets because Kuiper Belt objects formed in a colder region than Oort cloud comets.
The new findings of the Rosetta mission make it more likely that Earth got its water from asteroid-like bodies closer to our orbit and/or that Earth could actually preserve at least some of its original water in minerals and at the poles.
"Our finding also disqualifies the idea that Jupiter family comets contain solely Earth ocean-like water," said Kathrin Altwegg, principal investigator for the ROSINA instrument from the University of Bern, Switzerland, and lead author of the Science paper. "It supports models that include asteroids as the main delivery mechanism for Earth's oceans."
Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander obtained the first images taken from a comet's surface and will provide analysis of the comet's possible primordial composition. Rosetta will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even life.

Signs of Europa Plumes Remain Elusive in Search of Cassini Data

-- Data from Cassini's 2001 Jupiter flyby show Europa contributes less material to its surrounding environment than previously thought.
-- Unlike Saturn's known-active moon Enceladus, Europa is surrounded by very tenuous hot, excited gas.
A fresh look at data collected by NASA's Cassini spacecraft during its 2001 flyby of Jupiter shows that Europa's tenuous atmosphere is even thinner than previously thought and also suggests that the thin, hot gas around the moon does not show evidence of plume activity occurring at the time of the flyby. The new research provides a snapshot of Europa's state of activity at that time, and suggests that if there is plume activity, it is likely intermittent.
The Europa results are being presented today at the American Geophysical Union fall meeting in San Francisco and published in the Astrophysical Journal. Europa is considered one of the most exciting destinations in the solar system for future exploration because it shows strong indications of having an ocean beneath its icy crust.
Members of Cassini's ultraviolet imaging spectrograph (UVIS) team analyzed data collected by their instrument during the brief time it observed Europa in 2001, as Cassini sped through the Jupiter system en route to Saturn. The observations show that most of the hot, excited gas, or plasma, around Europa originates not from the moon itself, but from volcanoes on the nearby moon Io. In fact, from their data, the researchers calculated that Europa contributes 40 times less oxygen than previously thought to its surrounding environment.
"Our work shows that researchers have been overestimating the density of Europa's atmosphere by quite a bit," said Don Shemansky, a Cassini UVIS team member with Space Environment Technologies in Pasadena, California, who led the study. The team found that the moon's tenuous atmosphere, which was already thought to be millions of times thinner than Earth's atmosphere, is actually about 100 times less dense than those previous estimates.
A downward revision in the amount of oxygen Europa pumps into the environment around Jupiter would make it less likely that the moon is regularly venting plumes of water vapor high into orbit, especially at the time the data was acquired.
Scientists would expect that ongoing plume activity at Europa, as Cassini has observed at Saturn's moon Enceladus, would inject large amounts of water vapor into the area around Europa's orbit if the plumes were large enough, but that is not what UVIS observed.
"We found no evidence for water near Europa, even though we have readily detected it as it erupts in the plumes of Enceladus," said Larry Esposito, UVIS team lead at the University of Colorado at Boulder.
"It is certainly still possible that plume activity occurs, but that it is infrequent or the plumes are smaller than we see at Enceladus," said Amanda Hendrix, a Cassini UVIS team member with the Planetary Science Institute in Pasadena, who co-authored the new study. "If eruptive activity was occurring at the time of Cassini's flyby, it was at a level too low to be detectable by UVIS."
Indications of possible plume activity were reported in 2013 by researchers using NASA's Hubble Space Telescope, launching a wave of interest in searching for additional signs, including this effort by the UVIS team. Cassini's 2001 Jupiter flyby provided UVIS the opportunity to directly measure the environment near Europa, which is not possible with Hubble.
For more than a decade, Cassini's UVIS has observed the cold, dense doughnut of gas that encloses the orbit of Enceladus. There, the massive amount of gas being breathed into orbit around Saturn by the Enceladus plumes acts like a brake on electrons being dragged through it by Saturn's magnetic field, which rotates with the planet. This braking helps to keep down the temperature of the plasma. Apparently there is no such brake at Europa.
Since UVIS saw a hot plasma, rather than a cold one, around Europa's orbit, it suggests Europa is not outputting large amounts of gas -- including water.
Snapshots provided by missions that visited Jupiter prior to Cassini provided strong indications that Io is the major contributor of material to the environment around Jupiter, and indicated a hot, low density plasma surrounding Europa. The new results confirm that. "Io is the real monster here," Shemansky said.
"Europa is a complex, amazing world, and understanding it is challenging given the limited observations we have," said Curt Niebur, Outer Planets program scientist at NASA Headquarters in Washington. "Studies like this make the most of the data we have and help guide the kinds of of science investigations NASA should pursue in the future."
Scientists are currently using the Hubble Space Telescope to conduct an extensive six-month long survey looking for plume activity, and NASA is also studying various possible Europa missions for future exploration

NASA's Kepler Reborn, Makes First Exoplanet Find of New Mission

NASA's planet-hunting Kepler spacecraft makes a comeback with the discovery of the first exoplanet found using its new mission -- K2.
The discovery was made when astronomers and engineers devised an ingenious way to repurpose Kepler for the K2 mission and continue its search of the cosmos for other worlds.
"Last summer, the possibility of a scientifically productive mission for Kepler after its reaction wheel failure in its extended mission was not part of the conversation," said Paul Hertz, NASA's astrophysics division director at the agency's headquarters in Washington. "Today, thanks to an innovative idea and lots of hard work by the NASA and Ball Aerospace team, Kepler may well deliver the first candidates for follow-up study by the James Webb Space Telescope to characterize the atmospheres of distant worlds and search for signatures of life."
Lead researcher Andrew Vanderburg, a graduate student at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, studied publicly available data collected by the spacecraft during a test of K2 in February 2014. The discovery was confirmed with measurements taken by the HARPS-North spectrograph of the Telescopio Nazionale Galileo in the Canary Islands, which captured the wobble of the star caused by the planet's gravitational tug as it orbits.
The newly confirmed planet, HIP 116454b, is 2.5 times the diameter of Earth and follows a close, nine-day orbit around a star that is smaller and cooler than our sun, making the planet too hot for life as we know it. HIP 116454b and its star are 180 light-years from Earth, toward the constellation Pisces.
Kepler's onboard camera detects planets by looking for transits -- when a distant star dims slightly as a planet crosses in front of it. The smaller the planet, the weaker the dimming, so brightness measurements must be exquisitely precise. To enable that precision, the spacecraft must maintain steady pointing. In May 2013, data collection during Kepler's extended prime mission came to an end with the failure of the second of four reaction wheels, which are used to stabilize the spacecraft.
Rather than giving up on the stalwart spacecraft, a team of scientists and engineers crafted a resourceful strategy to use pressure from sunlight as a "virtual reaction wheel" to help control the spacecraft. The resulting K2 mission promises to not only continue Kepler's planet hunt, but also to expand the search to bright nearby stars that harbor planets that can be studied in detail, to help scientists better understand their composition. K2 also will introduce new opportunities to observe star clusters, active galaxies and supernovae.
Small planets like HIP 116454b, orbiting nearby bright stars, are a scientific sweet spot for K2 as they are good prospects for follow-up ground studies to obtain mass measurements. Using K2's size measurements and ground-based mass measurements, astronomers can calculate the density of a planet to determine whether it is likely a rocky, watery or gaseous world.
"The Kepler mission showed us that planets larger in size than Earth and smaller than Neptune are common in the galaxy, yet they are absent in our solar system," said Steve Howell, Kepler/K2 project scientist at NASA's Ames Research Center in Moffett Field, California. "K2 is uniquely positioned to dramatically refine our understanding of these alien worlds and further define the boundary between rocky worlds like Earth and ice giants like Neptune."
Since the K2 mission officially began in May 2014, it has observed more than 35,000 stars and collected data on star clusters, dense star-forming regions, and several planetary objects within our own solar system. It is currently in its third campaign.
The research paper reporting this discovery has been accepted for publication in The Astrophysical Journal.

Most of Earth's Water Came from Asteroids, Not Comets

Asteroids, not comets, may have delivered most of Earth's water to the planet when the solar system was young, new data from a probe orbiting a comet suggests.
Comets are some of the solar system's most primitive building blocks, with many dating to soon after its formation. Scientists think that these dirty snowballs probably helped seed Earth with key ingredients for life, such as organic compounds.
The European Space Agency's (ESA) Rosetta spacecraft is helping scientists learn more about the role these icy nomads have played in the evolution of the solar system and life on Earth by analyzing the composition of Comet 67P/Churyumov–Gerasimenko. In August, Rosetta became the first spacecraft to orbit a comet, and in November, its Philae lander became the first probe to make a soft touchdown on a comet's surface. Rosetta is also the first mission to escort a comet as it travels around the sun. [See images from ESA's Rosetta mission]

Now, Rosetta has helped solve a mystery about how Earth became the watery world it is today. Before Rosetta began orbiting Comet 67P/C-G in August, it was using an instrument known as ROSINA (short for Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) to analyze the chemical fingerprint of gases in the comet's fuzzy envelope. Scientists focused on data from the instrument regarding water to help uncover whether asteroids or comets delivered the water in Earth's oceans.

Heavy water on Earth and in comets

Models of Earth's birth suggestthat the planet was quite hot after its formation about 4.6 billion years ago, so scientists think it's unlikely that any water currently on Earth's surface dates back to the time of the planet's creation. However, prior studies have hinted that cosmic impacts could have easily brought water later, during a violent era known as the Late Heavy Bombardment, about 800 million years after Earth's formation.

To uncover the source of Earth's water, scientists look for bodies elsewhere in the solar system with similar water. Out of every 10,000 water molecules on Earth, three are not normal water molecules, but instead are so-called heavy water molecules.

A normal water molecule is made of two hydrogen atoms and one oxygen atom. In heavy water, a normal hydrogen atom is replaced with deuterium, which is like hydrogen except that it has an extra neutron in its nucleus. (A regular hydrogen atom has only one proton in its nucleus.)
To see if comets might be the source of Earth's water, in 1986, the ESA probe Giotto flew by Halley's Comet, becoming the first spacecraft to make close observations of a comet. It discovered that Halley's Comet had twice the amount of heavy water compared to normal water as Earth does.
Halley's Comet comes from the Oort Cloud, a giant spherical cloud of trillions of icy bodies that extends from 5,000 to 100,000 times the distance of Earth to the sun. The data from Halley's Comet and from other Oort Cloud comets "ruled out Oort Cloud comets as being the source of terrestrial water," said lead study author Kathrin Altwegg,of the University of Bern in Switzerland, principal investigator for the ROSINA mass spectrometer on Rosetta. [

But the Oort Cloud is not the only source of comets in the solar system. Another home to the dirty snowballs is the disc-shaped Kuiper Belt, which extends from about 30 to 55 times the distance of Earth to the sun. In 2011, data from ESA's Herschel Space Observatory revealed that Kuiper Belt comet 103P/Hartley 2 had a deuterium-to-hydrogen ratio "that matched terrestrial water's perfectly," Altwegg said during a news conference Tuesday (Dec. 9). "The Hartley 2 measurement — that was a real big surprise."

Not all comets are alike

Now, Rosetta has provided data from Comet 67P/C-G, another Kuiper Belt comet. However, Rosetta has discovered that this comet possesses an even higher deuterium-to-hydrogen ratio than seen in Oort Cloud comets — three times the amount of heavy water compared to normal water as Earth has.

This probably rules out Kuiper Belt comets from bringing water to Earth," Altwegg said. Instead, most of Earth's water was probably delivered by asteroids, Altwegg said.

"Today's asteroids have very little water — that's clear," Altwegg added. "But that was probably not always the case. During the Late Heavy Bombardment 3.8 billion years ago, at that time, asteroids could have had much more water than they could now."

The asteroids seen now "have stayed in the vicinity of the sun for 4.6 billion years," Altwegg said. "They've lost water due to the sun, due to heat. But to start with, they might have had much more water than they have now." Future analysis of ice-rich bodies in the asteroid belt could shed light on whether Earth's water really did come from there, Altwegg said.

The differences seen between Comet 103P/Hartley 2 and Comet 67P/C-G suggest that Kuiper Belt comets are much more diverse than previously thought. This could mean that "they were probably not all assembled in the same location in the solar system," Altwegg said. Kuiper Belt comets with relatively low deuterium-to-hydrogen ratios might have formed close to the sun, where solar warmth may have helped them lose deuterium, while those with relatively high deuterium-to-hydrogen ratios might have originated farther away.

In the future, when Comet 67P/C-G flies closer to the sun, the scientists hope to fly Rosetta through a jet of gas that the comet will give off as it gets warmer and more active. This will help reveal if the deuterium-to-hydrogen ratio seen from the water near the comet's surface is the same as that from near its core.

"Hopefully, we'll get to fly directly through a jet [in the] summertime [of] next year," said Matt Taylor, ESA Rosetta project scientist.

Where could Philae be?

Scientists are also still on the lookout for Philae, which made a bouncy landing on Comet 67P/C-G's surface in mid-November. The refrigerator-size probe's anchoring harpoons did not fire as planned during touchdown, and it bounced off the comet twice before settling down on its surface.
It broadcasted scientific data for about 57 hours on the comet's surface before its primary batteries ran out.
ESA officials aren't sure where Philae is now. Panoramic images from the probe reveal "one side of the lander appears to be in a hole," Taylor said during the news conference. "I see an overhanging clifflike structure."
A radio instrument known as CONSERT, short for Comet Nucleus Sounding Experiment by Radiowave Transmission, on both Rosetta and Philae has narrowed the lander's position to a strip a few hundred feet long by a few dozen feet wide.
"We're using that to kind of nail down where we think we should be looking harder," Taylor said. "Once we get identification of where the lander is, that will give us a better fix on what we believe the illumination conditions are and a better idea of when we should expect the lander to have sufficient illumination to start charging its batteries and come back online."
A "back-of-a-beer-mat calculation" suggests Philae might come back online around May, Taylor added.
The new comet findings are detailed in this week's issue of the journal Science

Saturn's Moons: What a Difference a Decade Makes

 

High res available here.

 

Rotating gif showing difference over 10 years & maps of  Mimas Enceladus Tethys Dione Rhea Iapetus  here.

 

 

Almost immediately after NASA's twin Voyager spacecraft made their brief visits to Saturn in the early 1980s, scientists were hungry for more. The Voyagers had offered them only a brief glimpse of a family of new worlds -- Saturn's icy moons -- and the researchers were eager to spend more time among those bodies.

The successor to the Voyagers at Saturn, NASA's Cassini spacecraft, has spent the past 10 years collecting images and other data as it has toured the Ringed Planet and its family of satellites. New color maps, produced from this trove of data, show that Cassini has essentially fulfilled one of its many mission objectives: producing global maps of Saturn's six major icy moons.

These are the large Saturnian moons, excluding haze-covered Titan, known before the start of the Space Age: Mimas, Enceladus, Tethys, Dione, Rhea and Iapetus. Aside from a gap in the north polar region of Enceladus (to be filled in next year), and some areas of Iapetus, this objective is now more or less complete.

The new maps are the best global, color maps of these moons to date, and the first to show natural brightness variations and high-resolution color together. Colors in the maps represent a broader range than human vision, extending slightly into infrared and ultraviolet wavelengths. Differences in color across the moons' surfaces that are subtle in natural-color views become much easier to study in these enhanced colors.

Cassini's enhanced color views have yielded several important discoveries about the icy moons. The most obvious are differences in color and brightness between the two hemispheres of Tethys, Dione and Rhea. The dark reddish colors on the moons' trailing hemispheres are due to alteration by charged particles and radiation in Saturn's magnetosphere. Except for Mimas and Iapetus, the blander leading hemispheres of these moons -- that is, the sides that always face forward as the moons orbit Saturn -- are all coated with icy dust from Saturn's E-ring, formed from tiny particles erupting from the south pole of Enceladus.

Enceladus itself displays a variety of colorful features. Some of the gas and dust being vented into space from large fractures near the moon's south pole returns to the surface and paints Enceladus with a fresh coating. The yellow and magenta tones in Cassini's color map are thought to be due to differences in the thickness of these deposits. Many of the most recently formed fractures on Enceladus, those near the south pole in particular, have a stronger ultraviolet signature, which appears bluish in these maps. Their color may be due to large-grained ice exposed on the surface, not unlike blue ice seen in some places in Earth's Arctic


Unlocking the Secrets of an Alien World's Magnetic Field

he strength of an alien world's magnetic field may have been deduced for the first time, by analyzing extraordinarily fast winds slamming against it from the planet's star, researchers say.

This research could help gauge the strength of other exoplanets' magnetic fields as well, scientists say.

The magnetic field of a planet can influence its evolution in crucial ways. "It works as a shield against stellar wind particles, which erode the atmosphere, so it is important to know if this field is big or small," said study lead author Kristina Kislyakova, a planetary scientist at the Austrian Academy of Sciences, in Graz.
In order to find out magnetic details about exoplanets — planets beyond our own solar system — Kislyakova and her colleagues investigated HD 209458b, which orbits a sunlike star in the constellation Pegasus about 150 light-years from Earth. This alien world is only about 70 percent the mass of Jupiter, but nearly 40 percent wider.

HD 209458b is a "hot Jupiter," a gas giant that orbits its star closer than Mercury does to the sun — specifically, HD 209458b circles its star at a distance of less than one-twentieth the distance between the sun and Earth. The extraordinary roasting that HD 209458b endures makes its atmosphere blow away like the tail of a comet. Astronomers have informally dubbed the world "Osiris," after the Egyptian god torn to pieces by his evil brother Set.

The researchers used NASA's Hubble Space Telescope to analyze the spectrum of light from HD 209458b as it passed in front of its star. Oddly, the data revealed hydrogen atoms moving away extremely quickly from the exoplanet in a lopsided manner.
To help explain the unusual way in which the hydrogen is blowing off HD 209458b, the scientists built a 3D model to account for all the known interactions between planetary atmospheres and stellar winds, the flow of particles that stream off stars. The model suggested the exoplanet had a magnetic field about 10 percent as strong as Jupiter's, and that the stellar wind blowing onto the planet was moving at about 895,000 mph (1.44 million km/h).

"The implication of these findings is improvement of our understanding of the worlds outside the solar system — some new light shed on bodies many light-years away from us," Kislyakova told Space.com.

Astronomers have confirmed more than 800 planets beyond our own solar system, and the discoveries keep rolling in. How much do you know about these exotic worlds?

These findings support prior research suggesting that hot Jupiters have relatively weak magnetic fields compared with their cooler gas giant cousins. Since hot Jupiters orbit very near their stars, they experience powerful gravitational pulls that likely slow the rates at which these hot Jupiters spin. This slower rotation should result in weaker magnetic fields, because a planet's magnetic field "is generated most effectively in fast-rotating cores of planets," Kislyakova said.

Beagle Located on Mars - Respect to Dr Colin Pillinger!

 



Image analysts are confident that the features seen are those of Beagle2

From BBC website

But the pictures suggest that all elements of the entry, descent and landing (EDL) system did a job.
The entry capsule clearly protected the probe from the heat of rubbing up against the Martian atmosphere, and the parachutes and bouncing bags must have come out to soften the final approach to the surface.
In the MRO images, it is even possible to identify some of the EDL elements on the ground close to Beagle.
The Commission of Inquiry - jointly set up by the European Space Agency (Esa) and the forerunner of what is now the UK Space Agency - blamed the failure on a mix of poor management and inadequate testing of systems and components. It also conceded that too little money had been allocated to the Beagle project at its outset.
With a total budget of near £50m, it remains one of the cheapest interplanetary missions ever devised.
The report's 19 recommendations included the demand that communications with future probes be maintained through the various descent phases.
This has become standard practice in recent years, but with Beagle its last contact was essentially that black and white photo of it moving away from the MEx orbiter six days prior to landing.
When Esa's ExoMars rover tries to land on the surface of the Red Planet in 2019, it will be relaying information all the way down.
The landing hardware for this mission is being built by the Russians, but its key sensor technologies, such as the descent radar, are being developed in Europe and will be tested on a demonstration landing in late 2016.
Esa director general Jean-Jacques Dordain told BBC News: "We have already taken a lot of lessons from the 'failure' of Beagle, and especially on the need to be connected, because if we had been connected in terms of communications we would have known we were on Planet Mars."
And reflecting on Colin Pillinger's role in the project he added: "It's a pity that he is not with us anymore, because this was his baby. And I'm really glad - really glad - [it's been found] for him."

Fresh Crater on Mars Spied by NASA Spacecraft (Photo)

This Mars Reconnaissance Orbiter image shows a new impact crater in Elysium Planitia that formed between February 2012 and June 2014.

A NASA Mars probe has photographed an impact crater that was blasted out of the Red Planet in just the last few years.

The HiRISE camera aboard NASA's Mars Reconnaissance Orbiter (MRO) captured the crater, which lies in the Red Planet's equatorial Elysium Planitia region, on Dec. 2, 2014. Scientists say the impact that gouged out the hole must have occurred between February 2012 and June 2014, based on previous images of the area.

The crater is about 40 feet (12 meters) wide, said HiRISE team member Ingrid Daubar of NASA's Jet Propulsion Laboratory in Pasadena, California.
"We've been finding new craters like this for a few years now, and from studying their frequency, we've come up with a cratering rate for Mars based on them," Daubar told Space.com via email.

"For craters this size (12 m diameter), we expect about 30 of these are forming over all of Mars each year," she added. "We only find a few of them, though, because we have to be looking in the right area. They're not as easy to find over non-dusty areas where they don't form these huge dark blast zones around the impact site."

The new photo is the first one HiRISE — short for High Resolution Imaging Science Experiment — has taken of the crater. The feature was actually discovered by MRO's Mars Context Camera, NASA officials said.

The objects that create Martian craters such as this one strike the surface at very high speeds — an average of 22,000 mph (35,400 km/h) — and are almost always completely destroyed in the process, Daubar said.

Indeed, there is no sign of the impactor in the new HiRISE photo. The silvery crescent toward the right side of the crater is just the illuminated interior wall of the crater, Daubar said. (In the image, sunlight is coming from the lower left.)

The $720 million MRO mission launched in August 2005 and arrived in orbit around Mars in March 2006. The spacecraft has been studying the Red Planet ever since with six scientific instruments. MRO also serves as a vital communications link between Earth and NASA's active Mars surface craft, the Opportunity and Curiosity rovers.

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution.
The view was previously released as a mosaic with lower resolution and strongly enhanced color (see PIA02590). To create this new version, the images were assembled into a realistic color view of the surface that approximates how Europa would appear to the human eye.
The scene shows the stunning diversity of Europa's surface geology. Long, linear cracks and ridges crisscross the surface, interrupted by regions of disrupted terrain where the surface ice crust has been broken up and re-frozen into new patterns.
Color variations across the surface are associated with differences in geologic feature type and location. For example, areas that appear blue or white contain relatively pure water ice, while reddish and brownish areas include non-ice components in higher concentrations. The polar regions, visible at the left and right of this view, are noticeably bluer than the more equatorial latitudes, which look more white. This color variation is thought to be due to differences in ice grain size in the two locations.
Images taken through near-infrared, green and violet filters have been combined to produce this view. The images have been corrected for light scattered outside of the image, to provide a color correction that is calibrated by wavelength. Gaps in the images have been filled with simulated color based on the color of nearby surface areas with similar terrain types.
This global color view consists of images acquired by the Galileo Solid-State Imaging (SSI) experiment on the spacecraft's first and fourteenth orbits through the Jupiter system, in 1995 and 1998, respectively. Image scale is 1 mile (1.6 kilometers) per pixel. North on Europa is at right.
The Galileo mission was managed by NASA's Jet Propulsion Laboratory in Pasadena, California, for the agency's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology, Pasadena.
Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://solarsystem.nasa.gov/galileo/. More information about Europa is available at http://solarsystem.nasa.gov/europa

Extreme Shrimp May Hold Clues to Alien Life

Shrimp called Rimicaris hybisae crawl on the Von Damm Spire, located 7,500 feet (2,300 meters) underwater in the Caribbean. The shrimp live in symbiosis with bacteria. This fascinating ecosystem gives scientists insights into what kind of life could thrive in extreme environments elsewhere, such as Jupiter's moon Europa. Credit: Courtesy Chris German, WHOI/NSF, NASA/ROV Jason © 2012 Woods Hole Oceanographic Institution

At one of the world's deepest undersea hydrothermal vents, tiny shrimp are piled on top of each other, layer upon layer, crawling on rock chimneys that spew hot water. Bacteria, inside the shrimps' mouths and in specially evolved gill covers, produce organic matter that feed the crustaceans.
Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, are studying this mysterious ecosystem in the Caribbean to get clues about what life could be like on other planetary bodies, such as Jupiter's icy moon Europa, which has a subsurface ocean.
"For two-thirds of the Earth's history, life has existed only as microbial life," said Max Coleman, senior research scientist at JPL. "On Europa, the best chance for life would be microbial."
The particular bacteria in the vents are able to survive in extreme environments because of chemosynthesis, a process that works in the absence of sunlight and involves organisms getting energy from chemical reactions. In this case, the bacteria use hydrogen sulfide, a chemical abundant at the vents, to make organic matter. The temperatures at the vents can climb up to a scorching 750 degrees Fahrenheit (400 degrees Celsius), but waters just an inch away are cool enough to support the shrimp. The shrimp are blind, but have thermal receptors in the backs of their heads.
"The overall objective of our research is to see how much life or biomass can be supported by the chemical energy of the hot submarine springs," Coleman said.
Hydrogen sulfide is toxic to organisms in high concentrations, but the bacteria feeding the shrimp need a certain amount of this chemical to survive. Nature has worked out a solution: The shrimp position themselves on the very border between normal, oxygenated ocean water and sulfide-rich water so that they and the bacteria can coexist in harmony.
"It's a remarkable symbiotic system," Coleman said.
Coleman was part of a team led by Chris German at the Woods Hole Oceanographic Institution, in Woods Hole, Massachusetts, that discovered these vents in 2009, off the west coast of Cuba. This research, funded under NASA's Astrobiology Science and Technology for Exploring Planets program, detected the vents by picking up the chemical signals of their plumes of water in the ocean.
The researchers returned in 2012 on the RV Atlantis with a robotic vehicle called Jason, supported by the National Science Foundation. Scientists collected extensive specimens from two hydrothermal vent fields: The Von Damm field at 7,500 feet (2,300 meters) and Piccard at more than 16,000 feet (4,900 meters), which is the world's deepest.
Coleman and collaborator Cindy Van Dover, marine biologist at Duke University, Durham, North Carolina, examined the shrimp for the first time when the same team returned in 2013 on the RV Falkor, provided by the Schmidt Ocean Institute in Palo Alto, California. Van Dover returned soon after using the robotic vehicle Hercules aboard the Exploration Vessel Nautilus, and did more collections and studies.
A bonus finding from studying this extreme oasis of life is that some of the shrimp, called Rimicaris hybisae, appear to be cannibalistic. The researchers discovered that when the shrimp arrange themselves in dense groups, bacteria seem to be the main food supplier, as the shrimp likely absorb the carbohydrates that the bacteria produce. But in areas where the shrimp are distributed more sparsely, the shrimp are more likely to turn carnivorous, eating snails, other crustaceans, and even each other.
Although the researchers did not directly observe Rimicaris hybisae practicing cannibalism, scientists did find bits of crustaceans in the shrimps' guts. And Rimicaris hybisae is the most abundant crustacean species in the area by far.
"Whether an animal like this could exist on Europa heavily depends on the actual amount of energy that's released there, through hydrothermal vents," said Emma Versteegh, a postdoctoral fellow at JPL.
The group received funding for shrimp-collecting expeditions from NASA's Astrobiology Science and Technology for Exploring Planets (ASTEP) program, through a project called "Oases for Life." That name is especially appropriate for this investigation, Coleman said.
"You go along the ocean bottom and there's nothing, effectively," Coleman said. "And then suddenly we get these hydrothermal vents and a massive ecosystem. It's just literally teeming with life."
This research was conducted in collaboration with the Woods Hole Oceanographic Institution and Duke University. The Schmidt Ocean Institute provided technical and financial support for marine and underwater robotic operations during the 2013 RV Falkor cruise. The California Institute of Technology in Pasadena manages JPL for NASA

Multiple pictures here

NASA's Curiosity Mars rover has completed a reconnaissance "walkabout" of the first outcrop it reached at the base of the mission's destination mountain and has begun a second pass examining selected rocks in the outcrop in more detail.
Exposed layers on the lower portion of Mount Sharp are expected to hold evidence about dramatic changes in the environmental evolution of Mars. That was a major reason NASA chose this area of Mars for this mission. The lowermost of these slices of time ascending the mountain includes a pale outcrop called "Pahrump Hills." It bears layers of diverse textures that the mission has been studying since Curiosity acquired a drilled sample from the outcrop in September.
In its first pass up this outcrop, Curiosity drove about 360 feet (110 meters), and scouted sites ranging about 30 feet (9 meters) in elevation. It evaluated potential study targets from a distance with mast-mounted cameras and a laser-firing spectrometer.
"We see a diversity of textures in this outcrop -- some parts finely layered and fine-grained, others more blocky with erosion-resistant ledges," said Curiosity Deputy Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. "Overlaid on that structure are compositional variations. Some of those variations were detected with our spectrometer. Others show themselves as apparent differences in cementation or as mineral veins. There's a lot to study here."

During a second pass up the outrcrop, the mission is using a close-up camera and spectrometer on the rover's arm to examine selected targets in more detail. The second-pass findings will feed into decisions about whether to drill into some target rocks during a third pass, to collect sample material for onboard laboratory analysis.
"The variations we've seen so far tell us that the environment was changing over time, both as the sediments were laid down and also after they hardened into bedrock," Vasavada said. "We have selected targets that we think give us the best chance of answering questions about how the sediments were deposited -- in standing water? flowing water? sand blowing in the wind? -- and about the composition during deposition and later changes."
The first target in the second pass is called "Pelona," a fine-grained, finely layered rock close to the September drilling target at the base of Pahrump Hills outcrop. The second is a more erosion-resistant ledge called "Pink Cliffs."
Before examining Pelona, researchers used Curiosity's wheels as a tool to expose a cross section of a nearby windblown ripple of dust and sand. One motive for this experiment was to learn why some ripples that Curiosity drove into earlier this year were more difficult to cross than anticipated.
While using the rover to investigate targets in Pahrump Hills, the rover team is also developing a work-around for possible loss of use of a device used for focusing the telescope on Curiosity's Chemistry and Camera (ChemCam) instrument, the laser-firing spectrometer.
Diagnostic data from ChemCam suggest weakening of the instrument's smaller laser. This is a continuous wave laser used for focusing the telescope before the more powerful laser is fired. The main laser induces a spark on the target it hits; light from the spark is received though the telescope and analyzed with spectrometers to identify chemical elements in the target. If the smaller laser has become too weak to continue using, the ChemCam team plans to test an alternative method: firing a few shots from the main laser while focusing the telescope, before performing the analysis. This would take advantage of more than 2,000 autofocus sequences ChemCam has completed on Mars, providing calibration points for the new procedure.
Curiosity landed on Mars in August 2012, but before beginning the drive toward Mount Sharp, the rover spent much of the mission's first year productively studying an area much closer to the landing site, but in the opposite direction. The mission accomplished its science goals in that Yellowknife Bay area. Analysis of drilled rocks there disclosed an ancient lakebed environment that, more than three billion years ago, offered ingredients and a chemical energy gradient favorable for microbes, if any existed there.
Curiosity spent its second year driving more than 5 miles (8 kilometers) from Yellowknife Bay to the base of Mount Sharp, with pauses at a few science waypoints.
NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. JPL, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA's Science Mission Directorate in Washington.
For more information about Curiosity, visit:
http://www.nasa.gov/msl
http://mars.jpl.nasa.gov/msl/

Geologic Maps of Vesta from NASA's Dawn Mission Published

Images from NASA's Dawn Mission have been used to create a series of high-resolution geological maps of the large asteroid Vesta, revealing the variety of surface features in unprecedented detail. These maps are included with a series of 11 scientific papers published this week in a special issue of the journal Icarus.
Geological mapping is a technique used to derive the geologic history of a planetary object from detailed analysis of surface morphology, topography, color and brightness information. A team of 14 scientists mapped the surface of Vesta using Dawn spacecraft data, led by three NASA-funded participating scientists: David A. Williams of Arizona State University, Tempe; R. Aileen Yingst of the Planetary Science Institute, Tucson, Arizona; and W. Brent Garry of the NASA Goddard Spaceflight Center, Greenbelt, Maryland.
"The geologic mapping campaign at Vesta took about two-and-a-half years to complete, and the resulting maps enabled us to recognize a geologic timescale of Vesta for comparison to other planets," said Williams.
Scientists discovered through these maps that impacts from several large meteorites have shaped Vesta's history. Asteroids like Vesta are remnants of the formation of the solar system, giving scientists a peek at its history. Asteroids could also harbor molecules that are the building blocks of life and reveal clues about the origins of life on Earth.
The geologic mapping of Vesta is enabled by images obtained by the framing camera provided by the Max Planck Institute for Solar System Research of the German Max Planck Society and the German Aerospace Center. This camera takes panchromatic images and seven bands of color-filtered images. Stereo photos are used to create topographic models of the surface that aid in the geologic interpretation.
Vesta's geologic timescale is determined by the sequence of large impact events, primarily by the Veneneia and Rheasilvia impacts in Vesta's early history and the Marcia impact in its late history. The oldest crust on Vesta pre-dates the Veneneia impact.The relative timescale is supplemented by model-based absolute ages from two different approaches that apply crater statistics to date the surface.
"This mapping was crucial for getting a better understanding of Vesta's geological history, as well as providing context for the compositional information that we received from other instruments on the spacecraft: the visible and infrared (VIR) mapping spectrometer and the gamma-ray and neutron detector (GRaND)," said Carol Raymond, Dawn's deputy principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, California.
The objective of NASA's Dawn mission is to characterize the two most massive objects in the main asteroid belt between Mars and Jupiter - Vesta and the dwarf planet Ceres. The spacecraft launched in 2007. Vesta, orbited by the Dawn spacecraft between July 2011 and September 2012, was thought to be the source of a unique set of basaltic meteorites (called HEDs, for howardite-eucrite-diogenite), and Dawn confirmed the Vesta-HED connection.
The Dawn spacecraft is currently on its way to Ceres, the largest object in the asteroid belt. Dawn will arrive at Ceres in March 2015.
Dawn uses ion propulsion in spiraling trajectories to travel from Earth to Vesta, orbit Vesta and then continue on to orbit the dwarf planet Ceres. Ion engines use very small amounts of onboard fuel, enabling a mission that would be unaffordable or impossible without them.
JPL manages the Dawn mission for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. The University of California at Los Angeles (UCLA) is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
For more information about Dawn, visit:
http://www.nasa.gov/dawn