Conspiracy theorists must face the truth of Mars hill
New images of the "face" on Mars have been obtained by Europe's Mars Express spacecraft. They reinforce what scientists thought from the beginning – that the face is just a naturally sculpted hill.
The "face" appeared in a photo of Mars's Cydonia region taken in 1976 by NASA's Viking 1 spacecraft. NASA scientists believed from the beginning that the feature was simply a hill that happened to look like a face because of the way the Sun cast shadows across it at the time the photo was taken.
However, the image sparked speculation that the face was built by aliens and that NASA was trying to cover it up.
The agency used the Mars Global Surveyor spacecraft to take new images of the region in 1998 and 2001. The new, much more detailed images showed a hill with no particular resemblance to a face (see Martian conspiracy theorists lose face).
But since the European Space Agency's Mars Express spacecraft arrived at Mars in 2003, many unconvinced members of the general public have been asking mission scientists to take more images of the feature.
"So many people wrote me emails – hundreds – saying, 'Why don't you image Cydonia, tell us the truth, we don't believe NASA,'" says Gerhard Neukum of the Free University of Berlin, Germany, chief scientist for Mars Express's High Resolution Stereo Camera (HRSC).
Mission controllers have been trying to get images of the region since 2004 but had been thwarted until recently by dust and haze in the atmosphere. Finally, on 22 July 2006, the team obtained clear images of the region with the HRSC.
By making observations of the area from slightly different angles as the spacecraft moved through its orbit, mission scientists have been able to build a 3D map of the "face" and the surrounding area.
Sculpted by erosion
The hill that sparked so much speculation is clearly seen in the new images to be a natural feature shaped by erosion, says Agustin Chicarro, ESA's chief scientist for Mars Express.
"My grandfather used to collect pieces of wood that look like birds or dogs or things like that," he told New Scientist. "This is the same thing – people get excited and see what they want to see. What has modelled these reliefs is simply erosion."
Neukum agrees. "It’s a mountainous structure and there's no artificial thing. These are mounds that have survived a general erosional process," he told New Scientist.
The whole area was once as high as the tops of the hills in the region, he says, but most of it has eroded down, with a few more resistant areas surviving as hills. The erosion is probably the result of ancient glaciers or perhaps liquid water carving into the rock, he says.
NASA Schedules Briefing to Announce Significant Find on Mars
WASHINGTON - NASA hosts a news briefing at 1 p.m. EST, Wednesday, Dec. 6, to present new science results from the Mars Global Surveyor. The briefing will take place in the NASA Headquarters auditorium located at 300 E Street, S.W. in Washington and carried live on NASA Television and www.nasa.gov.
The agency last week announced the spacecraft's mission may be at its end. Mars Global Surveyor has served the longest and been the most productive of any spacecraft ever sent to the red planet. Data gathered from the mission will continue to be analyzed by scientists.
- Michael Meyer -- Lead Scientist, Mars Exploration Program, NASA Headquarters, Washington
- Michael Malin -- President and Chief Scientist, Malin Space Science Systems, San Diego, Calif.
- Kenneth Edgett -- Scientist, Malin Space Science Systems
- Philip Christensen -- Professor, Arizona State University, Tempe, Ariz.
Reporters at participating agency field centers will be able to ask questions. For more information about NASA TV streaming video, downlink and schedule information, visit the web at:
All I'm reading is, "We have found some tantalizing glimpses of possible life signs and or water sources, which we have been holding back and hoarding against the day when our Mars Surveyor expedition finally packs in and we have to beg for much, much more monies, which could be spent on a myriad far more serious and relevant things, from our bankrupt Government."
Sorry. Could be wrong, of course, but the hype is coming thick and fast. New Moonbases and mention of the threat of China and India getting there first and etc. all seems to be heading towards the NASA Space Collection Plate Prayathon.
Water maybe ...or maybe not. depending on who you ask.
Water flowed 'recently' on Mars
Nasa says it has found "compelling" evidence that liquid water flowed recently on the surface of Mars.
The finding adds further weight to the idea that Mars might harbour the right conditions for life.
The appearance of gullies, revealed in orbital images from a Nasa probe, suggests that water could have flowed on the surface in the last few years.
But some scientists think these fresh gullies could also have been cut by liquid carbon dioxide (CO2).
The latest research emerged when Nasa's Mars Global Surveyor (MGS) spacecraft spotted gullies and trenches that scientists believed were geologically young and carved by fast-moving water coursing down cliffs and steep crater walls.
Scientists at the San Diego-based Malin Space Science Systems, who operate a camera aboard MGS decided to retake photos of thousands of gullies in search of evidence for recent water activity.
We're now realising Mars is more active than we previously thought, and that the mid-latitude section seems to be where all the action is
Phil Christensen, Arizona State University
Two gullies that were originally photographed in 1999 and 2001, and imaged again in 2004 and 2005, showed changes consistent with water flowing down the crater walls, according to the study.
In both cases, scientists found bright, light-coloured deposits in the gullies that were not present in the original photos. They concluded that the deposits - possibly mud, salt or frost - were left there when water recently cascaded through the channels.
Other scientists think it possible that gullies like this were caused not by water but by liquid carbon dioxide.
One of the reasons for favouring CO2 was that computer models of the Martian crust indicated water could exist only at depths of several kilometres. Liquid carbon dioxide, on the other hand, could persist much nearer the surface where temperatures can drop as low as -107C.
Prospects for life
Oded Aharonson, an assistant professor of planetary science at the California Institute of Technology (Caltech) said that while the interpretation of recent water activity on Mars was "compelling," it was just one possible explanation.
Aharonson said further study was needed to determine whether the deposits could have been left there by the flow of dust rather than water.
Deciding what was responsible for the features is a pressing question that has important consequences for the likelihood of life on Mars. Scientists have proposed that reservoirs of liquid water could exist beneath the Martian surface, providing a habitat for microbial life.
"This underscores the importance of searching for life on Mars, either present or past," said Bruce Jakosky, an astrobiologist at the University of Colorado at Boulder, who had no role in the study. "It's one more reason to think that life could be there."
Mars Global Surveyor abruptly lost radio contact with Earth last month. Attempts to locate the spacecraft, which has mapped the Red Planet since 1996, have failed, and scientists fear it is lost.
Nasa's Mars rovers, which landed in 2004, have sent scientists back equally strong evidence that liquid water flowed on the surface in ancient times, based on observations of alterations in ancient rocks.
"We're now realising Mars is more active than we previously thought, and that the mid-latitude section seems to be where all the action is," said Arizona State University scientist Phil Christensen, who was not part of the current research.
Details of the work appear in the journal Science.
Water flows on Mars, before our very eyes
18:00 06 December 2006
NewScientist.com news service
This 24-metre-wide crater was first spotted in December 2003. It was not present in an earlier image from April 2001 (Image: NASA/JPL/MSSS) Liquid water has flowed on the surface of Mars within the past five years, suggest images by the now lost Mars Global Surveyor (MGS). The results appear to boost the chances that Mars could harbour life.
In 1999, MGS spotted gullies carved on the sides of Martian slopes. Thousands of gullies have been imaged since then, most recently by the Mars Reconnaissance Orbiter (MRO) (see Stunning snaps from the best camera ever sent to Mars).
Many scientists believe the gullies were carved by liquid water, although others have argued they are due to avalanches of carbon dioxide gas or rivers of dust.
The gullies appear to have formed sometime in the past several hundred thousand years, since impact craters have not accumulated on top of them. But exactly how long ago material flowed through them has not been clear.
Now, new flows have appeared in two of the gullies monitored by MGS, showing that they have been active within the past several years. The research was led by Michael Malin of Malin Space Science Systems in San Diego, California, US. That company operates the Mars Orbiter Camera on MGS, which acquired the images.
Ice shellOne gully on a crater wall that was imaged in 2001 was found to have filled with light-coloured material when it was re-imaged in 2005. A similar new light-coloured deposit appears in a 2004 image of crater gullies previously imaged in 1999.
The researchers suggest the deposits were made by liquid water flowing out from beneath the surface. The researchers estimate that each flow would have involved 5 to 10 swimming pools' worth of water.
It would have been similar to a flash flood in the desert, says team member Ken Edgett of Malin Space Science Systems. "If you were there and this thing was coming down the slope, you'd probably want to get out of the way," he says.
Any liquid water exposed to Mars's atmosphere would quickly freeze, but Malin's team says even if the exterior of the flow rapidly freezes, water could continue flowing much farther inside this ice shell, developing into a thick mixture of ice and sediment that would eventually freeze completely.
Active todayIn Mars's thin atmosphere, ice left on the surface would quickly sublimate, changing from a solid to a gas, and disappear. But water vapour diffusing out from deeper in the mixture of ice and sediment could repeatedly coat the surface with frost, maintaining its light colour long enough for MGS to spot it, the researchers say.
Alternatively, salt deposited from salty water or sediment placed there by water flow may be responsible for the light colour.
MGS team member Phil Christensen of Arizona State University in Tempe, US, who was not involved in this study, says he is convinced that the gullies were formed by the action of liquid water.
"It says something is actively going on today in at least some of these gullies and one intriguing possibility is that water was released," he told New Scientist.
"I think they make a pretty good case that these aren't simply dust avalanches or some wind-related process," he says. He adds that the sublimating carbon dioxide scenario is even less likely, because temperatures in the regions where the gullies are found – between 30° and 60° from the equator – are too high for the gas to get frozen in the first place.
Just dust?Allan Treiman of the Lunar and Planetary Institute in Houston, Texas, US, agrees that something flowed recently to make the observed changes.
But he is not convinced that water was involved. "There is no direct evidence of water in the images – only that something flowed downhill. My money is on sand and dust, because there's lots and lots of sand and dust on Mars."
Streaks on slopes have been observed before and interpreted as the result of dust avalanches. But these appear to be a separate phenomenon from the new light-coloured gully deposits, the researchers say.
Newly formed dust streaks have been observed, but are always dark. The dust streaks are also usually observed in areas where the surface clearly has a thick coating that could be dust, unlike the two craters in question. And dust streaks have never been observed on the same slopes where gullies carve into the surface.
The formation of new gullies has been observed before also, but these were on the sides of sand dunes, and were more clearly related to avalanching sand (see Landslips, impacts and eroding ice revealed on Mars).
Melting snowIf the deposits are the result of liquid water flow, the source of the water is not clear. Malin's team suggests it comes from underground aquifers, perhaps kept liquid at low temperatures with the help of high salt concentrations.
Christensen says it could result from the removal of dust from a hypothetical layer of snow, which would then melt when exposed to sunlight.
The SHARAD radar on MRO is potentially capable of detecting any underground pockets of water that the flows might have come from, Malin says. "We're hopeful that as SHARAD flies of over these locations it may be able to detect these subsurface aquifers," he says.
The new evidence that liquid water may flow on Mars today boosts the chances that life could be present, Christensen says. "I believe that we have found places on Mars where you could take terrestrial life forms that live on snow or in aquifers and put them there and they would survive," he says.
Malin's team also reports in the same study the formation on Mars of 20 new craters between 2 and 150 metres across since 1999, confirming the previously estimated rate of crater formation and reinforcing the view that crater-free areas of Mars must truly be young or recently modified.
The discovery may be one of the last from MGS, which went silent shortly before its 10th launch anniversary in early November, and has not been heard from since (see Europe joins hunt for missing Mars probe).
Published online: 6 December 2006; |
Water could be flowing on Mars today
Photos show gullies growing within the past few years.
This gully has grown in the past few years.
Photographs snapped of Mars show gullies that must have grown sometime in the past seven years. That, researchers say, is strong evidence that liquid water is still flowing on the red planet today. And with running water comes a better chance of finding life.
Previous work had suggested that some gullies on the planet are new in geological terms. But that could have meant anything from millions of years ago to just yesterday. The latest data, collected by the orbiting Mars Global Surveyor (MGS) before its recent demise (see 'Goodbye Mars Global Surveyor'), suggest that water flows are happening now.
"Recognizing new contemporary processes is always a thrill," says Michael Malin of instrumentation company Malin Space Science Systems in San Diego, California, who led the investigation. "The current gully activity was anticipated, but to find it actually happening was very cool."
Scientists are a long way from finding any evidence of little green bacteria on Mars, but now, they say, they have a better idea where to look. "If I were looking for life on Mars, I'd bias my research in the direction of these features," says Mike Ravine, one of Malin's colleagues.
The same project has also revealed some 20 craters that have formed since 2004. An accidental snap with MGS's wide-angled camera in January 2006 caught a black smudge of the dust kicked up by an impact. Earlier high-resolution images of this area showed no crater — in later snaps there was a small one.
Getting data about how often craters form on the surface will help scientists to date other features on Mars by looking at the cratering there. "Knowing how old bits of the surface of Mars are helps us know what Mars did when," says Albert Haldemann, Mars exploration rover scientist at the Jet Propulsion Laboratory in Pasadena, California.
Mars was known to hold water — but in the form of ice. There are polar ice caps on the planet, and radar signals have hinted at underground ice.
The MGS pictures, analysed by Malin and his colleagues, show gullies that look very much like they have been formed by flowing liquid — they have finger-shaped branches and travel around obstacles just as a stream on Earth would do; and there are sedimentary deposits at the ends of the tracks.
One of the gullies was snapped first in 2001, and then again in 2005. During that time, about 300 metres of new deposits had been formed. In another gully, formed sometime between 1999 and 2004 in a crater in the Centauri Montes region, a number of finger-shaped branches appeared over an area of about 600 metres.
"It really is showing we're probably getting liquid water under current climate conditions," says Nathan Bridges, who works on the High Resolution Imaging Science Experiment (HiRise), which is flying onboard the Mars Reconnaissance Orbiter.
Though there are other features on the Martian surface that seem to have been produced by flowing water — deltas at the ends of river valleys and vast flood plains — they are far, far older than the gullies seem to be.
There is no definite explanation yet for how the gullies are forming, or where the water might be coming from.
The gullies could be formed from snow deposits, but Malin is betting on underground water sources. His guess is that water is being heated deep within the planet's crust and bursting out to form the gullies. The question remains how the water manages to stay liquid on the chilly surface of the planet, which averages temperatures of well below zero.
"It is possible, but we don't yet have evidence, that freezing point depressants are in solution," says Malin. Salt water, for example, freezes at a lower temperature than fresh, and martian water is expected to be very briny. Pockets of the surface might also trap a lot of sunlight, heating up a small area.
These things cannot be figured out from pictures. Landing on the planet and taking samples would be the best way to work out once and for all what is happening
HiRise will set up a sort of gully watch — it has already spotted some gullies in a region very near to one of Malin's finds, and there are plans to take pictures of these every few weeks.
Malin M. C., Edgett K. S., Posiolova L. V., McColley S. M.& Noe Dobrea E. Z., . Science, 314 . 1573 - 1577 (2006). doi:10.1126/science.1135156
Mars's Water Could Be Below Surface, Experts Say
for National Geographic News
January 25, 2007
Mars may hold large underground reservoirs of the water and carbon dioxide that once formed the planet's ancient atmosphere, new research suggests.
Stas Barabash and colleagues at the Swedish Institute of Space Physics have studied the Martian atmosphere with data from the European Space Agency's Mars Express orbiter.
The team determined that, of the water and carbon dioxide that once existed on the planet, only a small amount was likely lost to the effects of solar wind over the past 3.5 billion years.
Solar wind is the flow of charged particles that flows briskly from the sun (see a virtual solar system).
Writing tomorrow's issue of the journal Science, Barabash's team suggests that water and carbon dioxide reservoirs may therefore still exist on or below the Martian surface.
Further research into the planet's subsurface and atmosphere could reveal cricitial information about Mars's climate, they add.
"Knowing [more about the ancient Martian climate], we could speculate whether or not conditions were suitable for any complex structures [like organic materials] to develop.
"The question is thus directly related to the question of Mars's habitability.
"The origin of life, in my opinion, is the most important question the modern science is facing," Barabash said.
Mystery of Missing Water
Ancient Mars was much warmer, and wetter, place than it is today. Geological features indicate that large amounts of liquid water once existed on Mars, yet no one knows what became of them.
Three main theories attempt to explain the puzzle.
Some suggest that water and carbon dioxide still exist on Mars in large reservoirs that are as yet unfound—probably below the planet's surface.
Viking Mission May Have Missed Mars Life, Study Finds (October 23, 2006)
Mars Has Liquid Water, New Photos Suggest (December 6, 2006)
Photo Gallery of Mars
Other theories propose that some type of catastrophic cosmic impact removed much of the Martian atmosphere in a single event.
A third suggestion: Solar wind removed Martian water and carbon dioxide.
"I'm a plasma physicist so I really like the last one," said Barabash, a professor of experimental space physics.
"But our last study shows that escape [of water and carbon dioxide] from this channel is not as intense as we thought before, and that's a very big puzzle."
Some scientists caution that much more data is needed to make sense of the findings from Barabash's team.
"Recent measurements both from Mars Express and from Mars Global Surveyor suggest that we have not yet even described all of the loss processes at the present epoch," said Bruce Jakosky, from the Laboratory for Atmospheric and Space Physics at the University of Colorado.
"This means that we cannot yet determine the total loss rate today, let alone be able to extrapolate to earlier epochs."
Barabash also cautions that the solar wind may function in ways that scientists can't yet measure.
"It's possible that solar wind is far more complex than we think," he said. "So we have to explore other escape channels which are also associated with the solar wind."
Scientists using data from a European space probe orbiting Mars have produced new topographic maps of the Red Planet.
The "hiker's maps" provide detailed height contours and names of geological features on the Martian surface.
The European Space Agency (Esa), which compiled the maps, said it hoped the maps would become a standard reference for future research on the Red Planet.
The data, from the Mars Express spacecraft, has also been turned into 3-D models of the surface of Mars.
The topographic maps use contour lines to show the heights of the landscape.
The contour lines are superimposed upon high-resolution images of Mars, taken by the High-Resolution Stereo Camera (HRSC) aboard Mars Express.
The maps are much like those of Earth used by hikers and planning authorities.
The samples released by Esa show the Iani Chaos region of Mars because of its major topographical interest.
It is covered in individual blocks and hills that form a chaotic pattern across the landscape.
Mars Express entered orbit around the Red Planet in December 2003.
Water may have once flowed several kilometres beneath the surface of Mars in underground piping, according to new images of pipe-like fractures in bedrock taken by the most powerful camera in orbit around Mars.
Scientists have typically focused their hunt for signs of water on Mars on potential riverbeds, lakebeds and gullies. Now, these fractures could give planetary scientists a new place to look for signs of past water – and potentially life.
"These deeper underground areas may have been an oasis for any sort of biologic activity that may have been occurring," says Chris Okubo, a planetary scientist at the University of Arizona in Tucson, US.
The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter sees long, straight dark stripes on the walls of Candor Chasma, which is part of the giant canyon system Valles Marineris.
Underground aquiferThe stripes, about half a metre wide and as long as several kilometres, are cracks in the ground that may have formed from the weight of overlying rock that has since eroded away. An alternate explanation is that the fractures may have been caused by the faulting process that formed the 4000-kilometre-long Valles Marineris canyon.
Researchers believe the cracks were already there when a liquid – most likely water from an underground aquifer – flowed through them hundreds of millions to 1 billion years ago.
Evidence for the water comes from several observations. The cracks are flanked by light bands, called halos, between 5 and 10 metres wide.
Their light colour could be explained by bleaching. Acidic water flowing along the fractures would have stripped dark iron oxide minerals from the rock, making it lighter in colour.
Water oceans?Minerals in the water may also have been deposited in the rock, cementing the grains together and making them stronger and less vulnerable to erosion. This may explain why the halos are so well preserved while the surrounding rock has eroded over millions of years.
Previous observations have also found signs of water in Candor Chasma. In 2005, the Observatoire pour la Mineralogy, l'Eau, les Glaces et l'Activité (OMEGA) hyperspectral imager onboard Europe's Mars Express spacecraft spotted calcium-rich sulphates in that area.
These sulphates form in the presence of standing water over a long period, so in addition to an underground aquifer, water may have also existed in "oceans" on the surface (see Martian water clues go wider and deeper).
Since the initial images were taken, HiRISE has spotted extensive evidence for these kinds of features in layered rock elsewhere on the planet, primarily around Mars's equator.
Cemented togetherFor instance, it has seen fluid flow features in Victoria Crater just south of the equator (see photo above), where NASA's Opportunity rover is trudging along the rim (see Mars rover snaps panorama of yawning crater). The fractures appear to be surrounded by cemented rock on the eastern crater rim and floor.
One of NASA's goals for Opportunity is to get to that side of the crater. If it is able to get close enough, Opportunity might provide some microscopic observations of the rock to confirm whether the rock has been cemented together by fluid.
Okubo says that future spacecraft, such as NASA's Mars Science Laboratory, which is expected to head to the Red Planet in 2009, could land at some of the other layered deposits to get a closer look.
Since taking these images, HiRISE has actually experienced problems with its detectors, and managers are concerned that the problem could worsen (see Mars's top camera suffers worrying glitch).
Explanation: Black spots have been discovered on Mars that are so dark that nothing inside can be seen. Quite possibly, the spots are entrances to deep underground caves capable of protecting Martian life, were it to exist. The unusual hole pictured above was found on the slopes of the giant Martian volcano Arsia Mons. The above image was captured three weeks ago by the HiRISE instrument onboard the Mars Reconnaissance Orbiter currently circling Mars. The holes were originally identified on lower resolution images from the Mars Odyssey spacecraft, The above hole is about the size of a football field and is so deep that it is completely unilluminated by the Sun. Such holes and underground caves might be prime targets for future spacecraft, robots, and even the next generation of human interplanetary explorers.
See page for pic and more links:
This is news to me, and I guess will get a WTF! reaction from many Forteans!
We have such holes on Earth, but they are usually sink-holes, caused by water erosion in limestone regions.
JPL: asteroid on collision course with Mars www.chinaview.cn 2007-12-22 06:12:56
LOS ANGELES, Dec. 21 (Xinhua) -- The Jet Propulsion Laboratory (JPL) said on Friday that an asteroid may be on a collision course with Mars.
There is a 1-in-75 chance that the asteroid -- designated 2007 WD5 -- will smash into the Red Planet on Jan. 30, possibly blasting out a crater more than a half-mile wide, said JPL, headquartered in Passadena, Los Angeles.
"We estimate such impacts occur on Mars every thousand years or so," said Steve Chesley, a scientist at JPL.
Measuring about 164 feet wide, the asteroid currently is about half way between Earth and Mars, traveling at about 27,900 mph, said Don Yeomans, manager of the Near Earth Object Office at JPL.
"Over the next five weeks, we hope to gather more information from observatories so we can further refine the asteroid's trajectory," Yeomans said.
The Catalina Sky Survey, funded by the National Aeronautics Space Administration (NASA), first discovered 2007 WD5 on Nov. 20.The object was added to a "watch list" because its orbit passes near this planet, but scientists say it poses no danger to Earth.
If the asteroid does smash into Mars, it could release 3 megatons of energy -- roughly the magnitude generated by a similar encounter in Siberia in 1908. That blast is believed to have leveled 80 million trees spread across 830 miles (1,328 kilometers).
That space rock broke apart in the air, but an asteroid going through Mars' thinner atmosphere could hit the surface more or less intact.
If such a collision does occur, astronomers will have a front-row seat, thanks to the JPL-managed Mars Reconnaissance Orbiter currently mapping the Red Planet and two JPL-built rovers, which could take photographs from the Martian surface.