Ice found on Mercury's north pole
CAPE CANAVERAL, Fla. — Just in time for Christmas, scientists have confirmed a vast amount of ice at the north pole — on Mercury, the closest planet to the sun.
The findings are from NASA's Mercury-orbiting probe, Messenger, and the subject of three scientific papers released on Thursday by the journal Science.
The frozen water is located in regions of Mercury's north pole that always are in shadows, essentially impact craters. It's believed the south pole harbors ice as well, though there are no hard data to support it. Messenger orbits much closer to the north pole than the south.
“If you add it all up, you have on the order of 100 billion to 1 trillion metric tons of ice,” said David Lawrence of the Applied Physics Laboratory at Johns Hopkins University. “The uncertainty on that number is just how deep it goes.”
The ice is thought to be at least 1½ feet deep — and possibly as much as 65 feet deep.
There's enough polar ice at Mercury, in fact, to bury an area the size of Washington, D.C., by two to 2½ miles deep, said Lawrence, the lead author of one of the papers.
“These are very exciting results,” he added at a news conference.
For two decades, radar measurements taken from Earth have suggested the presence of ice at Mercury's poles. Now scientists know for sure, thanks to Messenger, the first spacecraft to orbit Mercury.
The water almost certainly arrived with impacting comets, or possibly asteroids. Ice is found at the surface, as well as buried under a dark material.
Messenger was launched in 2004 and went into orbit 1½ years ago around Mercury, where temperatures reach 800 degrees. NASA hopes to continue observations well into next year.
Columbia University's Sean Solomon, principal scientist for Messenger, stressed that no one is suggesting that Mercury might hold evidence of life, given the presence of water. But the latest findings may help explain how water and other building blocks of life arrived elsewhere in the solar system, he said.
Mercury is becoming the subject of new interest “where it wasn't much of one before,” Solomon said.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.