Looks like there’s water ice on Mercury. That’s right, Mercury.
The U.S. Government Printing Office (along with Book Revue in Huntington, L.I.) was one of my great discoveries in college. One book I picked up from USGPO was a slim volume of photos from the Mariner 10 mission to Venus and Mercury. Even before Mariner got there we knew that Mercury was an inhospitable place. The spacecraft’s two fly bys of the planet in 1974 showed us that in addition to being blasted by solar radiation, our innermost planet had also been pummeled by debris from space for millenia, leaving a heavily cratered surface.
NASA (that’s NASA, not a guy called Nasa, but an acronym for a government agency, the “National Aeronautics and Space Administration) put its Messenger spacecraft into orbit around Mercury in the Spring of 2011. Since then it has been gathering data about the planet, including the results of spectrography that, combined with radar studies done from Earth, indicate there’s water ice in some of the deep craters at Mercury’s poles. The final piece of the puzzle was supplied by the probe’s Mercury Laser Altimeter (MLA — everything has an acronym, some of them unpronouceable, so get used to it!) that measured the reflectivity of the material down inside those polar craters.
Gregory Neumann and his colleagues at NASA’s Goddard Space Flight Center in Greenbelt, Md., built the instrument. He says it’s basically a bright flashlight. “We can use it to measure reflectance — places where the imagers can’t see anything because it’s dark,” says Neumann.
When they shined their laser flashlight into the craters, they saw was something that looked very much like ice.
This article on NASA’s Messenger web site provides full details, including images, supporting this discovery.
Man, I really love science.
Where did the ice come from? Some scientists propose it could be from inside the planet. Others that it has been left by icy comets that have crashed into Mercury on the end of their journey around the Sun.
One thing’s for sure, if there’s water ice on Mercury the stuff may be everywhere in the solar system (well, obviously not on the 900 degree Venusian surface).
Kind of makes you wonder if steam powered spaceships might not be such a bad idea after all.