Images from the visible light camera on NASAs Mars Odyssey spacecraft, combined with images from the Mars Global Surveyor (MGS), suggest melting snow is the likely cause of the numerous eroded gullies first documented on Mars by the Mars Orbiting Camera in 2000 by the MGS orbiter.The now-famous Martian gullies were created by trickling water from melting snow packs, not underground springs or pressurized flows, as has been previously suggested, argues Dr. Philip Christensen, the principal investigator for Odysseys camera system and a Professor at Arizona State University in Tempe. He proposes gullies are carved by water melting and flowing beneath snow packs, where it is sheltered from rapid evaporation in the planets thin atmosphere. His paper is in the electronic February 19 issue of Nature.Looking at an image of an impact crater in the southern mid-latitudes of Mars, Christensen noted eroded gullies on the craters cold, pole-facing northern wall and immediately next to them a section of what he calls "pasted-on terrain." Such unique terrain represents a smooth deposit of material that Mars researchers have concluded is "volatile" (composed of materials that evaporate in the thin Mars atmosphere), because it characteristically occurs only in the coldest, most sheltered areas. The most likely composition of this slowly evaporating material is snow. Christensen suspected a special relationship between the gullies and the snow.
http://www.nasa.gov/HP_news_03075.html
Wednesday, February 19, 2003
Popular Posts
-
...These measures, based on the US Digital Millennium Copyright Act (DMCA) give far too much power to publishers, at the expense of individu...
-
William Gibson's latest novel, Spook Country is awesome. Not as frantic or kinetic as Pattern Recognition or All Tomorrow's Parti...
-
The challenge of having the United States as a neighbour was one of the topics discussed Tuesday during a meeting with Mexican President Vic...
-
This is not bad. A mix of 70s rock and 80s punk with some good lyrics. Songs range from boring to excellent. Id give it a B+. http://www.ama...
-
Here's my (edited) journal entry for this event dated 12/01/98: Wow. I just sessioned and started reading "The Tao of Physics"...
-
nother bottle of the doublewood -- arguably one of my favorite scotches. Balvenie just doesnt make a bad blend. A fab birthday gift from my ...
-
Finally went out and picked up a Nintendo Wii. My god the thing is fun. Ridiculously, ludicrously fun. Hiyat and I had to tear ourselves...
-
"The International Space Station will have ultra-sensitive clocks on board, and it is a good place to test the theory," said Dr. A...
-
This is from a 1932 episode of The Little Rascals . Man, I've had jobs like that. http://www.boingboing.net/2007/10/23/perpetually...
-
OK, if you have to go, this is the way to do it. Just like Spock in Star Trek II: The Wrath Of Khan. I'm serious. http://www.eter...