Feeds

Martian ice swaps poles every 25,000 years

Give or take

The next step in data security

Water-ice on Mars swaps poles over a cycle that spans 51,000 years or so, in step with the way the planet precesses, or wobbles around on its axis.

Researchers investigating the different types of ice at the Martian poles plugged new data from the Mars Express mission into a model of the planet's climate. Then, adding in details of the planet's slow precession, they ran the clock back 21,500 years to a time when the northern summer was closest to the sun, the exact opposite of the situation today.

Martian water now, and 21,500 years ago: ESA

Martian water now, and 21,500 years ago.

As time passed, the model showed water accumulation rates shifting across the globe. Water at the north pole became unstable and vaporised easily, moving to the southern hemisphere where it recondensed and froze on the surface. Here, over the course of 10,000 years, it formed an ice cap up to six metres thick.

Run the clock forward towards today, and the opposite starts to happen: the ice at the south vaporises and shifts on the winds to the north. The process was interrupted about 1,000 years ago, the researchers say, when for some reason a layer of carbon dioxide ice formed a protective layer over the ice, preventing further erosion.

The model helps explain newly discovered deposits of ice at the southern pole, spotted by the OMEGA instrument early on in the Mars Express mission.

The European Space Agency says the "perennial deposits of water-ice" have built up on top of million-year old layered terrain, and argues that their presence is strong evidence for recent glacial activity. ®

Choosing a cloud hosting partner with confidence

More from The Register

next story
SCREW YOU, Russia! NASA lobs $6.8bn at Boeing AND SpaceX to run space station taxis
Musk charging nearly half as much as Boeing for crew trips
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Thought that last dinosaur was BIG? This one's bloody ENORMOUS
Weighed several adult elephants, contend boffins
Edge Research Lab to tackle chilly LOHAN's final test flight
Our US allies to probe potential Vulture 2 servo freeze
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
India's MOM Mars mission makes final course correction
Mangalyaan probe will feel the burn of orbital insertion on September 24th
Cracked it - Vulture 2 power podule fires servos for 4 HOURS
Pixhawk avionics juice issue sorted, onwards to Spaceport America
City hidden beneath England's Stonehenge had HUMAN ABATTOIR. And a pub
Boozed-up ancients drank beer before tearing corpses apart
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Security and trust: The backbone of doing business over the internet
Explores the current state of website security and the contributions Symantec is making to help organizations protect critical data and build trust with customers.