News / Science & Technology

Snowmelt May Have Caused Martian Valleys

Water-carved valleys on Mars appear to have been caused by runoff from precipitation, likely meltwater from snow. Early Martian precipitation would have fallen on mountainsides and crater rims.
Water-carved valleys on Mars appear to have been caused by runoff from precipitation, likely meltwater from snow. Early Martian precipitation would have fallen on mountainsides and crater rims.

Related Articles

Video Dry Ice Surfs Martian Dunes

Dry ice forms a 'lubricating layer' of gaseous carbon dioxide that allows chunks to glide down dunes

Water-Ice Clouds Activate Martian Atmosphere

There is more water vapor in the Martian atmosphere than in the upper layers of Earth's

Evidence of Martian Ocean Mounts

The ocean could have covered as much as a third of the planet
VOA News
Ancient runoff from melting snow may have been the cause for many of the valleys branching across Mars.

Researchers at Brown University believe many of the valleys were created runoff of what they call “orographic precipitation” -- when warm, humid air is pushed up a mountain and deposits rain or snow.

The source of Martian water has long been debated among scientists, with some thinking the water may have bubbled up from underground. The new study makes the case for precipitation. 

Researchers looked at four areas along tall Martian mountain ridges or raised crater rims.

They then had to make a theoretical model to assess the direction of the prevailing winds in the ancient Martian atmosphere. The model simulated air movement based on the gas composition of Martian air. Once that was established the research team created a model to predict the where precipitation was likely to have fallen.

According to the models, the precipitation would have been heaviest at the heads of the most dense valley networks.

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

The models indicated a climate cold enough to cause the precipitation to be snow, but the researchers said periodic warming conditions could have caused episodic rain.

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

The research was published in the Geophysical Research Letters.

You May Like

Video On the Scene: In Gaza, Darkness Brings Dread and Death

Palestinians fear nighttime raids, many feel abandoned by outside world, VOA's Scott Bobb reports More

African Small Farmers Could Be Key to Ending Food Insecurity

Experts say providing access to microloans, crop insurance, better storage facilities, irrigation, road systems and market information could enable greater production More

University of Michigan Wins Solar Car Race

Squad guided its student-designed solar-powered vehicle to fifth consecutive time victory in eight-day bi-annual American Solar Challenge More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Vietnamese Staging Chinese Product Boycott After Oil Rig Spati
X
Reasey Poch
July 28, 2014 7:18 PM
China recently pulled an oil rig from an area of the disputed South China Sea that Vietnam also claims. Despite the action, the incident has had a lingering effect on consumers in Vietnam. VOA's Reasey Poch reports from Hanoi on an effort to boycott Chinese products.
Video

Video Vietnamese Staging Chinese Product Boycott After Oil Rig Spat

China recently pulled an oil rig from an area of the disputed South China Sea that Vietnam also claims. Despite the action, the incident has had a lingering effect on consumers in Vietnam. VOA's Reasey Poch reports from Hanoi on an effort to boycott Chinese products.
Video

Video ESA Spacecraft to Land on a Comet

After a long flight through deep space, a European Space Agency probe is finally approaching its target -- a comet millions of kilometers away from earth. Scientists say the mission may lead to some startling discoveries about the origins of the water on earth. VOA’s George Putic has more.
Video

Video Young Africans Arrive in US for Leadership Program

President Barack Obama's Young African Leadership Initiative has brought hundreds of young Africans to the United States for a six-week program aimed at building their knowledge and skills in fields such as public administration and business. Out of the 50,000 young Africans who applied for the program, just one percent was accepted. VOA's Laurel Bowman caught up with some of those who made the cut and has this report.
Video

Video In Honduras, Amnesty Rumors Fuel US Migration Surges

False rumors in Central America are fueling the current surge of undocumented young people being apprehended at the U.S. border. The inaccurate claims suggest the U.S. will give amnesty to young migrants from the region. As VOA's Brian Padden reports from Honduras, these rumors trace back to President Obama's 2012 executive order to halt deportations for some young undocumented immigrants already living in the United States.
Video

Video Students in Business for Themselves

They're only high school students, but they are making accessories for shoes, fabricating backpacks and doing product photography - all through their own businesses. It's the result of a partnership between a non-profit organization that teaches entrepreneurship and their schools. VOA's Mike O'Sullivan and Deyane Moses met the budding entrepreneurs near Los Angeles.
Video

Video Astronauts Train in Underwater Lab

In the world’s only underwater laboratory, four U.S. astronauts train for a planned visit to an asteroid. The lab - called Aquarius- is located five kilometers off Key Largo, in southern Florida. Living in close quarters and making excursions only into the surrounding ocean, they try to simulate the daily routine of a crew that will someday travel to collect samples of a rock orbiting far away from earth. VOA’s George Putic has more.

AppleAndroid