<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><div style="margin: 0px; font-size: 12px; font-family: Courier; "><span style="font-family: Helvetica; "></span><span style="letter-spacing: 0.0px">* <b>Mars Reconnaissance Orbiter Mission</b> - September 11, 2012</span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; color: rgb(47, 47, 47); "><span style="letter-spacing: 0.0px"><b>NASA Orbiter Observations Point to 'Dry Ice' Snowfall on Mars</b></span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Courier; color: rgb(47, 47, 47); "><span style="letter-spacing: 0.0px; color: #000000">"</span><span style="letter-spacing: 0.0px">PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter data have given scientists the clearest evidence yet of carbon-dioxide snowfalls on Mars. This reveals the only known example of carbon-dioxide snow falling anywhere in our solar system.</span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; color: rgb(47, 47, 47); min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><p style="margin: 0px 0px 8px; font-size: 12px; font-family: Courier; color: rgb(47, 47, 47); "><span style="letter-spacing: 0.0px">Frozen carbon dioxide, better known as "dry ice," requires temperatures of about minus 193 degrees Fahrenheit (minus 125 Celsius), which is much colder than needed for freezing water. Carbon-dioxide snow reminds scientists that although some parts of Mars may look quite Earth-like, the Red Planet is very different. The report is being published in the Journal of Geophysical Research.</span></p><p style="margin: 0px 0px 8px; font-size: 12px; font-family: Courier; color: rgb(47, 47, 47); "><span style="letter-spacing: 0.0px">"These are the first definitive detections of carbon-dioxide snow clouds," said the report's lead author, Paul Hayne of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We firmly establish the clouds are composed of carbon dioxide -- flakes of Martian air -- and they are thick enough to result in snowfall accumulation at the surface."</span></p><p style="margin: 0px 0px 8px; font-size: 12px; font-family: Courier; color: rgb(47, 47, 47); "><span style="letter-spacing: 0.0px">The snowfalls occurred from clouds around the Red Planet's south pole in winter. The presence of carbon-dioxide ice in Mars' seasonal and residual southern polar caps has been known for decades. Also, NASA's Phoenix Lander mission in 2008 observed falling water-ice snow on northern Mars.</span><span style="letter-spacing: 0.0px; color: #000000">"</span></p><div style="margin: 0px; font-size: 12px; font-family: Courier; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Courier; "><span style="letter-spacing: 0.0px"><b>MARS RECONNAISSANCE ORBITER HIRISE IMAGES</b></span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Courier; "><span style="letter-spacing: 0.0px">All of the HiRISE images are archived here:</span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; color: rgb(4, 51, 255); "><span style="text-decoration: underline ; letter-spacing: 0.0px"><a href="http://hirise.lpl.arizona.edu/">http://hirise.lpl.arizona.edu/</a></span><span style="letter-spacing: 0.0px; color: #000000">.</span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Courier; "><span style="letter-spacing: 0.0px">More information about the MRO mission is available online at <a href="http://www.nasa.gov/mro"><span style="letter-spacing: 0px; color: rgb(4, 51, 255); ">http://www.nasa.gov/mro</span></a>.</span></div><div style="margin: 0px; font-size: 12px; font-family: Courier; min-height: 14px; "><span style="letter-spacing: 0.0px"></span><br></div><div style="margin: 0px; font-size: 12px; font-family: Courier; "><span style="font-family: Helvetica; "></span></div></body></html>