A Planet of Fire and (Ice?)

Radar Image of Suspected Water Ice on Mercury
Credit: National Astronomy and Ionosphere Center

At first glance, the solar system’s innermost planet generally conjures up images of a blistering hot, sun-baked ball of rock which would be one of the last places one would expect to find water ice.  That was considered to be the case until 1991, when the Arecibo radar telescope in Puerto Rico, as well as NASA’s Goldstone/VLA  detected reflections from Mercury which appeared to indicate the presence of water ice in deep craters near the planet’s poles.  The finding could not be confirmed at the time however, because the only spacecraft to visit the planet,  NASA’s Mariner 10 mission in 1974-1975 was only able to image about 45% of the total surface, making it impossible to get an accurate map of crater walls, and corresponding locations of deep cold.

At a press conference held yesterday,  a NASA/JPL team reported that based on findings by the Messenger spacecraft, which entered into orbit around Mercury in 2011, the presence of ice at multiple locations on the planet can now be confirmed.  Locked in permanent shadow by surrounding crater walls, the ice was most likely deposited by meteorites during a period of heavy bombardment several billion years ago.

Although the presence of crater-ice on Mercury is of extremely limited value in terms of the future human expansion into the inner solar system, what it implies about the possible presence of ice elsewhere, such as lower latitude craters on both the Moon and Mars is particularly encouraging. Substantial deposits of ice in such locations could function as a relative oasis in the desert, enabling the growth of outposts both small and large, depending on the size of the deposit, and the relative balance of that which is consumed for fuel, and that which is incorporated into closed loop recycling systems.

When that day comes, the less exciting than its sounds field of space law may find itself the battleground for a fascinating debate over who does, and who does not, have the right to exercise control over extra-terrestrial resources. With wars having been fought over less, much less;  it is not too much of a stretch to imagine that lying somewhere out there, buried in cratered ice on the Moon or Mars is the seed of the next Declaration of Independence. For  whom and from what?  TBD.