Barry Eitel

Last week, astronomers claimed that they had sufficient evidence that Mercury, the inner-most planet in the Solar System, was probably harboring tons of ice.

For years, Earthlings always had the feeling that we were special because we were soaking wet with water. We called ourselves the “blue marble.” Water means life, and as far as we can tell, we’re the only planet with life. At least for light-years around.

However, it appears water is not so special to Earth. The latest discovery of frozen water around Mercury’s poles means that water might be a very common compound in the Solar System and beyond.

We all know what happened because of the water on Earth…stuff started swimming in it.

Scientists postulated about Mercurial waters from data collected by the Messenger spacecraft. Three independent pieces of evidence came to the same wet conclusion.

Messenger measured excess hydrogen at Mercury's north pole using its Neutron Spectrometer. The spacecraft also measured the reflectance of Mercury's polar deposits at near-infrared wavelengths with the Mercury Laser Altimeter (MLA). Finally, the MLA helped scientists model the surface and near-surface temperatures of Mercury's north polar regions.

In the permanently shadowed polar regions of Mercury (always facing away from the sun), there could be 100 billion to a trillion tons of ice.

“The more we examine the solar system, the more we realize it’s a soggy place,” said Jim Green, director of NASA’s Planetary Science Division, in a press conference.

"The neutron data indicate that Mercury's radar-bright polar deposits contain, on average, a hydrogen-rich layer more than tens of centimeters thick beneath a surficial layer 10 to 20 centimeters thick that is less rich in hydrogen," writes David Lawrence, a Messenger Participating Scientist and the lead author of one of the papers. "The buried layer has a hydrogen content consistent with nearly pure water ice."

"For more than 20 years the jury has been deliberating on whether the planet closest to the Sun hosts abundant water ice in its permanently shadowed polar regions. Messenger has now supplied a unanimous affirmative verdict," claimed Sean Solomon, principal investigator of the Messenger mission

"But the new observations have also raised new questions," pondered Solomon. "Do the dark materials in the polar deposits consist mostly of organic compounds? What kind of chemical reactions has that material experienced? Are there any regions on or within Mercury that might have both liquid water and organic compounds? Only with the continued exploration of Mercury can we hope to make progress on these new questions."