Posted on 06/26/2006 8:12:36 PM PDT by DaveTesla
Scientists have suspected in recent years that Mars might be undergoing some sort of global warming. New data points to the possibility it is emerging from an ice age.
NASA's Mars Odyssey orbiter has been surveying the planet for nearly a full Martian year now, and it has spotted seasonal changes like the advance and retreat of polar ice. It's also gathering data of a possible longer trend.
There appears to be too much frozen water at low-latitude regions -- away from the frigid poles -- given the current climate of Mars. The situation is not in equilibrium, said William Feldman of the Los Alamos National Laboratory.
"One explanation could be that Mars is just coming out of an ice age," Feldman said. "In some low-latitude areas, the ice has already dissipated. In others, that process is slower and hasn't reached an equilibrium yet. Those areas are like the patches of snow you sometimes see persisting in protected spots long after the last snowfall of the winter."
Frozen water makes up as much as 10 percent of the top 3 feet (1 meter) of surface material in some regions close to the equator. Dust deposits may be covering and insulating the lingering ice, Feldman said.
Feldman is the lead scientist for an Odyssey instrument that assesses water content indirectly through measurements of neutron emissions. He and other Odyssey scientists described their recent findings today at the fall meeting of the American Geophysical Union in San Francisco.
"Odyssey is giving us indications of recent global climate change in Mars," said Jeffrey Plaut, project scientist for the mission at NASA's Jet Propulsion Laboratory.
High latitude regions of Mars have layers with differing ice content within the top 20 inches (half-meter) or so of the surface, researchers conclude from mapping of hydrogen abundance based on gamma-ray emissions.
"A model that fits the data has three layers near the surface," said William Boynton of the University of Arizona, Tucson, team leader for the gamma-ray spectrometer instrument on Odyssey. "The very top layer would be dry, with no ice. The next layer would contain ice in the pore spaces between grains of soil. Beneath that would be a very ice-rich layer, 60 to nearly 100 percent water ice."
Boynton interprets the iciest layer as a deposit of snow or frost, mixed with a little windblown dust, from an era when the climate was colder than nowadays. The middle layer could be the result of changes brought in a warmer era, when ice down to a certain depth dissipated into the atmosphere. The dust left behind collapsed into a soil layer with limited pore space for returning ice.
More study is needed to determine for sure what's going on.
Other Odyssey instruments are providing other pieces of the puzzle. Images from the orbiter's camera system have been combined into the highest resolution complete map ever made of Mars' south polar region.
"We can now accurately count craters in the layered materials of the polar regions to get an idea how old they are," said Phil Christensen of Arizona State University, Tempe, principal investigator for the camera system.
Temperature information from the camera system's infrared imaging has produced a surprise about dark patches that dot bright expanses of seasonal carbon-dioxide ice.
"Those dark features look like places where the ice has gone away, but thermal infrared maps show that even the dark areas have temperatures so low they must be carbon-dioxide ice." Christensen said. "One possibility is that the ice is clear in these areas and we're seeing down through the ice to features underneath."
Layered deposits covering older, cratered surfaces near Mars' south pole dominate this image taken last month. The margin of these layered deposits appears to be eroding poleward, exposing a series of layers in the retreating cliff. It is one piece of a puzzle scientists are putting together on an apparently changing Martian climate.
An Inconvinient Truth!
We really need to get these Martians to stop driving their SUV's so much.
Well, you know whose fault this is...
Yeah, it's that dratted internal combustion engine at work again.
An ignored truth.
Why not, any weather changes that have happened on earth are directly caused by the sun as well, why not Mars?
Or does mars also have a methane, carbon dioxide problem, and a Martian AL GorP?
LOL
It's Americas fault!
The greenhouse emmissions from those Mars Landers are to blame.
Obviously we need a treaty, whereby America agrees to ground it's space program. Nobody else needs to - just America.
For the children.
ping
Bump
I remember reading last year that the sun has become extremely active in the past 100 years or so. Energy output had been the highest recorded in the last century or so. The sun itself has not necessarily gotten hotter, but the energy it puts out has increased dramatically. That energy interacts with the atmosphere (i.e. northern lights) and can and does warm the atmosphere.
The global warming crowd always tends to ignore the biggest source of global warming there is: the sun.
It's like if the sun's making things hotter here it might be making things hotter there?
Manbearpig has been spotted on Mars! DAMN YOU MANBEARPIG!
I saw a pretty well done docu-detective sort of piece, might have been on the Discovery channel, a while ago.
The movie went to elaborate lengths, to basically prove that the dark ages were indeed dark, that the earth was plunged into a global tailspin of altered climate and famine - by the massive eruption somewhere around the year 600 was it? Of the Indonesian supervolcano Krakatau.
(I know it erupted bigtime in 1820 or so, but this was evidently a previous explosive eruption of the entire Krakatau caldera)
They even went so far as to posit, that the plague was able to take root in Europe in part, because of the altered and cooler climate.
If (and it seemed plausible) one volcano could alter the climate on earth so signficantly - would it not seem that "global warming" is temporary if it exists, and will likely be reversed by the next super volcano.
Even Pinatubo had an effect far beyond Luzon.
BTW: Krakatau is busy even now, rebuilding...
It's Bush's Fault
It's our fault for sending up all those Mars landers. They're worse than SUVs.
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