The Martian Decade

Tomorrow, the latest spacecraft bound for Mars will launch from the Kennedy Space Center, one of the three ground rovers and four satellites that, barring anything unexpected, will converge on the Red Planet by early next year. In the meantime, the satellites currently orbiting Mars are sending back a wealth of information and pictures. If all goes well, the next few years should yield a flood of data about our planetary neighbor.

The Odyssey, which showed the presence of water at Mars' southern pole, has detected much larger amounts of water at the northern pole, greatly increasing the odds of finding microbial traces of Martian life.

"Once the carbon-dioxide layer disappears, we see even more water ice in northern latitudes than Odyssey found last year in southern latitudes," said Odyssey's Dr. Igor Mitrofanov of the Russian Space Research Institute, Moscow, lead author of a paper in the June 27 issue of the journal Science. "In some places, the water-ice content is more than 90 percent by volume." [...] Another report, to be published in the Journal of Geophysical Research-Planets, combines measurements from Odyssey and Global Surveyor to provide indications of how densely the winter layer of carbon-dioxide frost or snow is packed at northern latitudes greater than 85 degrees. The Odyssey data are used to estimate the mass of the deposit, which can then be compared with the thickness to obtain a density. The dry ice layer appears to have a fluffy texture, like freshly fallen snow, according to the report by Dr. William Feldman of Los Alamos National Laboratory, N.M., and 11 co-authors. The study also found once the dry ice disappears, the remaining surface near the pole is composed almost entirely of water ice.

Also, the Global Surveyor satellite has sent back a couple of striking photographs. One is of the tiny Martian moon, Phobos, one of the darkest objects in the solar system and only 0.006 times the size of our moon (17x14x11 miles, 27x22x18 km). The other is a stunningly clear picture of a meteor impact crater clearly showing the presence of layers of sedimentary rock, which may indicate the former presence of a giant lake.

Fascinating...