NASA’s Messenger spacecraft has sent an intriguing message back to Earth from Mercury: There’s water ice and organic compounds on the planet closest to the Sun.
New observations by the MESSENGER spacecraft provide compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters.
Three independent lines of evidence support this conclusion: the first measurements of excess hydrogen at Mercury’s north pole with MESSENGER’s Neutron Spectrometer, the first measurements of the reflectance of Mercury’s polar deposits at near-infrared wavelengths with the Mercury Laser Altimeter (MLA), and the first detailed models of the surface and near-surface temperatures of Mercury’s north polar regions that utilize the actual topography of Mercury’s surface measured by the MLA. These findings are presented in three papers published online today in Science Express.
Neumann and his colleagues report that the first MLA measurements of the shadowed north polar regions reveal irregular dark and bright deposits at near-infrared wavelength near Mercury’s north pole.
According to Paige, the dark material is likely a mix of complex organic compounds delivered to Mercury by the impacts of comets and volatile-rich asteroids, the same objects that likely delivered water to the innermost planet.The organic material may have been darkened further by exposure to the harsh radiation at Mercury’s surface, even in permanently shadowed areas.
Both the ice and organics likely came from comets slamming into Mercury at points in the past. Ice can exist on the planet because of its extreme environment. Its sunward side bakes at 800 degrees F, but its night side and poles are deep freezes at -300. Stuff that falls in craters, or slams into the planet to create craters, in the polar regions tends to get frozen forever.
The presence of water ice at the poles does suggest that spacecraft could extract the oxygen to refuel there. While you’re gassing up it’s probably not a good idea to step out for a little sun without serious protection. If you stepped into the sunlight you’d burst into *flames.
There has been speculation that the Mars rover Curiosity found organics in the soil of the red planet, but that was shot down yesterday. Whatever Curiosity has found, it’s not organics. Maybe the rover found one of the many lost orbiters sent to check the place out. Or Jimmy Hoffa.
At any rate, organics ended up being found on Mercury first.
*Or, you would, if Mercury had an atmosphere capable of supporting flames, which it doesn’t. But it’s still lethally hot. Maybe we can convince Harry Reid there’s a cowboy poetry festival there that he just has to attend.