Feeds

NASA confirms ice at poles of Mercury

Astrobiologists probe tiniest planet in 'soggy' solar system

High performance access to file storage

NASA's backronymic MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) orbiter has detected ice in polar craters on Mercury, and has confirmed the finding with multiple methods.

What looked like ice on the poles of Mercury was detected in 1991 by the Arecibo radio telescope, and NASA said this March that more evidence for ice was coming from MESSENGER. But now three peer-reviewed papers have shown that water ice is almost certainly there.

"One of the major objectives of the MESSENGER mission was to test the idea, now 20 years old, that water deposits matching ice are on Mercury," said MESSENGER principal investigator Sean Solomon at a press conference on Thursday.

"We know of no other compound that matches the radar data, neuron readings, thermal signature, and reflectivity of the substance other than ice." In the careful language NASA always uses, this is as definite a statement as you'll get on the topic until we land a rover on the wee planet.

MESSENGER has been scanning Mercury's surface with a variety of tools, and NASA said the first evidence for ice came from the probe's Neutron Spectrometer. This found a hydrogen-rich layer of land, covered by a darker coating, which indicated a layer of ice between 50cm and 20 meters thick.

David Lawrence, MESSENGER participating scientist, said that the substance could amount to between 100 billion and a trillion tons of ice at Mercury's northern pole. That's enough ice to bury Washington DC in a layer two miles thick, he said.

The other line of icy evidence comes from MESSENGER's Mercury Laser Altimeter (MLA), which has fired over 10 million laser pulses at Mercury's surface and picked up their bounce-backs to build a topological and reflective map of the planet.

Mercury North pole

There's ice, but sadly no Santa

The MLA findings show that the areas thought to contain ice have two to four times the reflective capability of the normal surface of Mercury. The surface mapping also outlined deep polar craters, such as the Prokofiev crater, which never receive sunlight and so could keep ice cool enough to survive.

Mercury has the widest temperature range of any planet in the solar system. At noon on the equator typical temperatures are around 700 Kelvin, and this only drops off to 550 Kelvin near the poles. But in permanently shadowed areas the temperature dips to just 50 Kelvin, which is plenty cool enough to freeze water and stop it evaporating.

The discovery adds to the increasing amount of evidence that our solar system is a "relatively soggy place," as one official put it. Its outer edges are packed full of icy comets and it is hypothesized that these bring water – and in Earth's case, at least, possibly the building blocks for life itself – in towards the sun.

"No one is saying there's life on Mercury," explained Solomon. "But history of life depends on the delivery of water to a planet, and then some chemistry we still don’t understand on our own planet, let alone others. Nevertheless Mercury is now becoming an object of astrobiological study." ®

High performance access to file storage

More from The Register

next story
Video games make you NASTY AND VIOLENT
Especially if you are bad at them and keep losing
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.