New insight into Martian environment
July 18, 2008 NASA’s $720 million Mars Reconnaissance Orbiter has provided groundbreaking insight into the environmental makeup of the planet during its earliest geological age. Images from the MRO reveal that the Red Planet was originally a muddy brown, with vast lakes and flowing rivers covering a predominantly clay surface. Meanwhile, the Phoenix Lander has successfully collected frozen ice shavings with its robotic arm.
The MRO was launched in 2005, attained Martian orbit in March 2006, and began its primary science phase in November 2006. Its sophisticated imaging equipment was pivotal in choosing the site of the Phoenix Lander. CRISM, the Compact Reconnaissance Imaging Spectrometer for Mars, was the MRO instrument that delivered the latest discovery. The visible-infrared spectrometer produced detailed maps of the surface mineralogy of Mars, revealing the presence of phyllosilicate materials, clay-like substances that scientists believe were created and distributed by water.
The phyllosilicates date back to the Noachian period, approximately 4.6 to 3.8 billion years ago, and cover vast regions of the ancient highlands of Mars, roughly half of the planet. CRISM, which has higher spatial and spectral resolutions than any previous spectrometer sent to Mars, was able to identify kaolinite, chlorite, illite or muscovite, and a new class of hydrated silicate. These phyllosilicate materials can only form in the presence of water and, according to a study released by the scientists in the July 16 issue of Nature, “point to a rich diversity of Noachian environments conducive to habitability.”
"The minerals present in Mars' ancient crust show a variety of wet environments," said John Mustard, a member of the CRISM team from Brown University, and lead author of the Nature study. "In most locations the rocks are lightly altered by liquid water, but in a few locations they have been so altered that a great deal of water must have flushed though the rocks and soil. This is really exciting because we're finding dozens of sites where future missions can land to understand if Mars was ever habitable and if so, to look for signs of past life."
On the surface of the red planet, the Phoenix Lander continues to diligently scrape away at the frozen soil and ice. In an exciting recent development, the Robotic Arm Camera has recorded that shaved material in the scoop has changed slightly over time – indicating either that the sample is settling, or that its properties are changing as a result of exposure. The Lander is currently making preparations to introduce the sample to its Thermal and Evolved-Gas Analyzer oven, where the properties of the material can be studied in more detail.