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

Tired of Waiting, South Africans Demand Change ‘Now’

With chronic poverty and lack of basic services largely fueling recent xenophobic attacks, many in Rainbow Nation say it’s time for government to act More

Challenges Ahead for China's Development Plans in Pakistan

Planned $46 billion in energy and infrastructure investments in Pakistan are aimed at transforming the country into a regional hub for trade and investment More

'Forbidden City' Revisits Little Known Era of Asian-American Entertainment

Little-known chapter of entertainment history captured in 80s documentary is revisited in new digitally remastered format and book 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.
Cinema That Crosses Borders Showcased at Tribeca Film Festivali
X
April 24, 2015 4:09 AM
Among the nearly 100 feature length films being shown at this year’s Tribeca Film Festival in New York City are more than 20 documentaries and features with international appeal, from a film about a Congolese businessman in China, to documentaries shot in Pakistan and diaspora communities in the U.S., to a poetic look at disaffected South African youth. VOA’s Carolyn Weaver has more.
Video

Video Cinema That Crosses Borders Showcased at Tribeca Film Festival

Among the nearly 100 feature length films being shown at this year’s Tribeca Film Festival in New York City are more than 20 documentaries and features with international appeal, from a film about a Congolese businessman in China, to documentaries shot in Pakistan and diaspora communities in the U.S., to a poetic look at disaffected South African youth. VOA’s Carolyn Weaver has more.
Video

Video UN Confronts Threat of Young Radicals

The radicalization and recruitment of young people into Islamist extremist groups has become a growing challenge for governments worldwide. On Thursday, the U.N. Security Council heard from experts on the issue, which has become a potent threat to international peace and security. VOA’s Margaret Besheer reports.
Video

Video Growing Numbers of Turks Discover Armenian Ancestry

In a climate of improved tolerance, growing numbers of people in Turkey are discovering their grandmothers were Armenian. Hundreds of thousands of Armenians escaped the mass deportations and slaughter of the early 1900's by forced conversion to Islam. Or, Armenian children were taken in by Turkish families and assimilated. Now their stories are increasingly being heard. Dorian Jones reports from Istanbul that the revelations are viewed as an important step.
Video

Video Migrants Trek Through Western Balkans to Reach EU

Migrants from Africa and other places are finding different routes into the European Union in search of a better life. The Associated Press followed one clandestine group to document their trek through the western Balkans to Hungary. Zlatica Hoke reports that the migrants started using that route about four years ago. Since then, it has become the second-most popular path into Western Europe, after the option of sailing from North Africa to Italy.
Video

Video TIME Magazine Honors Activists, Pioneers Seen as Influential

TIME Magazine has released its list of celebrities, leaders and activists, whom it deems the world’s “most influential” in 2015. VOA's Ramon Taylor reports from New York.
Video

Video US Businesses See Cuba as New Frontier

The Obama administration's opening toward Cuba is giving U.S. companies hope they'll be able to do business in Cuba despite the continuation of the U.S. economic embargo against the communist nation. Some American companies have been able to export some products to Cuba, but the recent lifting of Cuba's terrorism designation could relax other restrictions. As VOA's Daniela Schrier reports, corporate heavy hitters are lining up to head across the Florida Straits - though experts urge caution.
Video

Video Kenya Launches Police Recruitment Drive After Terror Attacks

Kenya launched a major police recruitment drive this week as part of a large-scale effort to boost security following a recent spate of terror attacks. VOA’s Gabe Joselow reports that allegations of corruption in the process are raising old concerns about the integrity of Kenya’s security forces.
Video

Video Japan, China in Race for Asia High-Speed Rail Projects

A lucrative competition is underway in Asia for billions of dollars in high-speed rail projects. Cambodia, India, Indonesia, Malaysia Thailand and Vietnam are among the countries planning to move onto the fast track. They are negotiating with Japan and the upstart Chinese who are locked in a duel to revolutionize transportation across Asia. VOA Correspondent Steve Herman in Bangkok has details.
Video

Video Scientists: Mosquitoes Attracted By Our Genes

Some people always seem to get bitten by mosquitoes more than others. Now, scientists have proved that is really the case - and they say it’s all because of genes. It’s hoped the research might lead to new preventative treatments for diseases like malaria, as Henry Ridgwell reports from London.
Video

Video Bible Museum Coming to Washington DC

Washington is the center of American political power and also home to some of the nation’s most visited museums. A new one that will showcase the Bible has skeptics questioning the motives of its conservative Christian funders. VOA religion correspondent Jerome Socolovsky reports.
Video

Video Armenia and Politics of Word 'Genocide'

A century ago this April, hundreds of thousands of Armenians of the Turkish Ottoman empire were deported and massacred, and their culture erased from their traditional lands. While broadly accepted by the U.N. and at least 20 countries as “genocide”, the United States and Turkey have resisted using that word to describe the atrocities that stretched from 1915 to 1923. But Armenians have never forgotten.
Video

Video Afghan First Lady Pledges No Roll Back on Women's Rights

Afghan First Lady Rula Ghani, named one of Time's 100 Most Influential, says women should take part in talks with Taliban. VOA's Rokhsar Azamee has more from Kabul.
Video

Video Keeping Washington Airspace Safe Is Tall Order

Being the home of all three branches of the U.S. federal government makes Washington, D.C. the prime target for those who want to make their messages and ideas heard. Unfortunately, many of them choose to deliver them in unorthodox ways, including from the air, as a recent incident clearly showed involving a gyrocopter landing on the Capitol’s West Lawn. VOA's George Putic has more.
Video

Video New Brain Mapping Techniques Could Ease Chronic Pain

From Boulder, Colorado, Shelley Schlender reports that new methods for mapping pain in the brain are providing validation for chronic pain and might someday guide better treatment.
Video

Video Hope, Prayer Enter Fight Against S. Africa Xenophobia

South Africa has been swept by disturbing attacks on foreign nationals. Some blame the attacks on a legacy of colonialism, while others say the economy is to blame. Whatever the cause, ordinary South Africans - and South African residents from around the world - say they're praying for the siege of violence to end. Anita Powell reports from Johannesburg.

VOA Blogs