Feeds

Boffins DREAMING of a WHITE CHRISTMAS ... on MARS!

Snow, not groundwater, could have carved red world's valleys

Intelligent flash storage arrays

Brown University boffins reckon that some Martian valleys could have been carved by snowfall - rather than rivers running across the Red Planet's surface.

Water-carved valleys on Mars appear to have been caused by runoff from precipitation

Not a weird cheese, but evidence of Martian valleys being carved by rainfall runoff

Although scientists now tend to agree that water once flowed on the planet, researchers are still unsure if that water came from below Mars' surface - groundwater - or from precipitation and runoff, like melted snowfall flowing down mountains.

A new study found that valleys at four different locations near tall mountain ridges or crater rims on Mars seem to have been made by meltwater from snow, or possibly rainfall. The researchers used a newly developed general circulation model (GCM) for the Red Planet to figure out the direction of prevailing winds at each place and then ran simulations of orographic precipitation to show where the wind would have caused snow and rain to fall.

Orographic precipitation is snow or rain that falls when moist prevailing winds are pushed up by mountain ridges. The simulations showed that the precipitation would have been heaviest at the heads of the valley networks.

“Their drainage density varies in the way you would expect from the complex response of precipitation to topography,” geological sciences graduate student Kat Scanlon said. “We were able to confirm that in a pretty solid way.”

Scanlon did her graduate work in meteorology in Hawaii, which has a typical orographic precipitation pattern. On the island, wet tropical winds from the east are pushed up by the mountains but run out of energy before reaching the top - so they dump their rain on the eastern side, creating a tropical jungle. The western edge is practically a desert because it sits in the rain shadow cast by the mountain's peak.

Similar patterns could have been at work on Mars, but the boffins still have to figure out if the model they used for the planet's weather holds up. The GCM they used predicts a cold climate, so the simulations were done with snow, which could have melted to form the networks - or occasionally been supplemented by rain.

“The next step is to do some snowmelt modelling,” Scanlon said. “The question is how fast can you melt a giant snowbank? Do you need rain? Is it even possible to get enough discharge [to carve the valleys] with just the snowmelt?”

The researchers hope the answers can help to firm up theories of what the Martian climate was like billions of years ago.

The study, "Orographic precipitation in valley network headwaters: Constraints on the ancient Martian atmosphere", was published in Geophysical Research Letters. ®

Providing a secure and efficient Helpdesk

More from The Register

next story
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
You can crunch it all you like, but the answer is NOT always in the data
Hear that, 'data journalists'? Our analytics prof holds forth
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
America's super-secret X-37B plane returns to Earth after nearly TWO YEARS aloft
674 days in space for US Air Force's mystery orbital vehicle
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.