News / Science & Technology

    Powerful Volcanoes Raise New Questions About Ancient Mars

    The largest canyon in the Solar System cuts a wide swath across the face of Mars.(NASA)
    The largest canyon in the Solar System cuts a wide swath across the face of Mars.(NASA)
    Reuters
    Ancient Mars was home to giant volcanoes capable of eruptions a thousand times more powerful than the one that shook Mount St. Helens in 1980, scientists said on Wednesday.
     
    The finding raises fresh questions about conditions on Mars in its early years, a time when scientists believe the planet was much more Earth-like with a thick atmosphere, warmer temperatures and water on its surface.
     
    Major volcanic eruptions likely would have triggered climate shifts that toggled Martian temperatures between cold spells when ash blocked sunlight and heat waves when greenhouse gasses filled the skies, according to scientists.
     
    Supervolcanoes may have made it more difficult for life to evolve on the planet's surface, but underground steam vents and the release of water into the atmosphere also could have created niches for microbes to thrive, said geologist Joseph Michalski of the Planetary Science Institute in Tucson, Arizona.
     
    The discovery of supervolcanoes on Mars comes from analysis of images from a quartet of Mars orbiters over the past 15 years.
     
    These types of volcanoes, also known as “caldera” volcanoes, are ancient, collapsed structures rather than steep, cone-shaped or domed mountains like Olympus Mons on Mars, a so-called shield volcano that stands nearly three times taller than Mount Everest, the highest peak on Earth.
     
    “We know a lot about the volcanic history of Mars over the last 3 billion to 3.5 billion years, but that still leaves about one billion years before that over which we don't really know anything about volcanism,” Michalski said.
     
    Some scientists theorized that the oldest Martian volcanoes had eroded away, but the new findings suggest a different kind of volcano existed long ago.
     
    “If early Mars saw a lot more explosive volcanism, then the features that are left from that don't look like those shield volcanoes. That's maybe why we didn't see them,” Michalski said.
     
    Scientists say supervolcanoes erupt with about 1,000 times the force of typical volcanoes like Mount St. Helens in Washington state. The eruption of Mount St. Helens in 1980 blasted the top off the mountain, killed 57 people and, according to the U.S. Geological Survey, shot ash, steam, water and debris about 80,000 feet (24,000 meters) into the air.
     
    Evidence of past supervolcanoes on Earth has been erased by plate tectonics and other geologic activities.
     
    Michalski actually was studying Martian impact craters, not looking for volcanoes.
     
    “We made the discovery by accident,” he said. “As I went through [the images] of this one region, I found a number of them that were simply not impact craters,” he said.
     
    “One was clearly a volcano. ... It is quite possible there are many more of these,” Michalski added.
     
    Because the emission of gasses from volcanoes helps create a planet's atmosphere, understanding the volcanic history of Mars is crucial to figuring out what the planet - the fourth from the Sun - was like in its early years.
     
    Additional evidence may come from NASA's Mars Curiosity rover, which is heading toward a three-mile (five-km) high mound of deposits called Mount Sharp.
     
    The rover touched down inside a giant impact basin near the planet's equator in August 2012 to assess if Mars ever had the chemistry and environment to support and preserve microbial life.
     
    “There are thousands of layers of rocks in Mount Sharp and they contain a long record of geologic history,” Michalski said.
     
    “There could be interlayered rocks that are ash beds, and we predict that and we hope that the rover can test it,” he said.
     
    The research appears in the journal Nature.

    You May Like

    Former US Envoys Urge Obama to Delay Troop Cuts in Afghanistan

    Keeping troop levels up during conflict with both Taliban and Islamic State is necessary to support Kabul government, they say

    First Lady to Visit Africa to Promote Girls' Education

    Michele Obama will be joined by daughters and actresses Meryl Streep and Freida Pinto

    Video NYSE Analyst: Brexit Will Continue to Place Pressure on Markets

    Despite orderly pricing and execution strategy at the New York Stock Exchange, analyst explains added pressure on world financial markets is likely

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Brexit Vote Plunges Global Markets Into Uncharted Territoryi
    X
    June 24, 2016 9:38 PM
    British voters plunged global markets into unknown territory after they voted Thursday to leave the European Union. The results of the Brexit vote, the term coined to describe the referendum, caught many off guard. Analysts say the resulting volatility could last for weeks, perhaps longer. Mil Arcega reports.
    Video

    Video Brexit Vote Plunges Global Markets Into Uncharted Territory

    British voters plunged global markets into unknown territory after they voted Thursday to leave the European Union. The results of the Brexit vote, the term coined to describe the referendum, caught many off guard. Analysts say the resulting volatility could last for weeks, perhaps longer. Mil Arcega reports.
    Video

    Video Orlando Shooting Changes Debate on Gun Control

    It’s been nearly two weeks since the largest mass shooting ever in the United States. Despite public calls for tighter gun control laws, Congress is at an impasse. Democratic lawmakers resorted to a 1960s civil rights tactic to portray their frustration. VOA’s Carolyn Presutti explains how the Orlando, Florida shooting is changing the debate.
    Video

    Video Tunisian Fishing Town Searches for Jobs, Local Development Solutions

    As the European Union tries to come to grips with its migrant crisis, some newcomers are leaving voluntarily. But those returning to their home countries face an uncertain future.  Five years after Tunisia's revolution, the tiny North African country is struggling with unrest, soaring unemployment and plummeting growth. From the southern Tunisian fishing town of Zarzis, Lisa Bryant takes a look for VOA at a search for local solutions.
    Video

    Video 'American Troops' in Russia Despite Tensions

    Historic battle re-enactment is a niche hobby with a fair number of adherents in Russia where past military victories are played-up by the Kremlin as a show of national strength. But, one group of World War II re-enactors in Moscow has the rare distinction of choosing to play western ally troops. VOA's Daniel Schearf explains.
    Video

    Video Experts: Very Few Killed in US Gun Violence Are Victims of Mass Shootings

    The deadly shooting at a Florida nightclub has reignited the debate in the U.S. over gun control. Although Congress doesn't provide government health agencies funds to study gun violence, public health experts say private research has helped them learn some things about the issue. VOA's Carol Pearson reports.
    Video

    Video Trump Unleashes Broadside Against Clinton to Try to Ease GOP Doubts

    Recent public opinion polls show Republican Donald Trump slipping behind Democrat Hillary Clinton in the presidential election matchup for November. Trump trails her both in fundraising and campaign organization, but he's intensifying his attacks on the former secretary of state. VOA National Correspondent Jim Malone reports.
    Video

    Video Muslim American Mayor Calls for Tolerance

    Syrian-born Mohamed Khairullah describes himself as "an American mayor who happens to be Muslim." As the three-term mayor of Prospect Park, New Jersey, he believes his town of 6,000 is an example of how ethnicity and religious beliefs should not determine a community's leadership. Ramon Taylor has this report from Prospect Park.
    Video

    Video Internal Rifts Over Syria Policy Could Be Headache for Next US President

    With the Obama administration showing little outward enthusiasm for adopting a more robust Syria policy, there is a strong likelihood that the internal discontent expressed by State Department employees will roll over to the next administration. VOA State Department correspondent Pam Dockins reports.
    Video

    Video Senegal to Park Colorful ‘Cars Rapide’ Permanently

    Brightly painted cars rapide are a hallmark of Dakar, offering residents a cheap way to get around the capital city since 1976. But the privately owned minibuses are scheduled to be parked for good in late 2018, as Ricci Shryock reports for VOA.
    Video

    Video Florida Gets $1 Million in Emergency Government Funding for Orlando

    The U.S. government has granted $1 million in emergency funding to the state of Florida to cover the costs linked to the June 12 massacre in Orlando. U.S. Attorney General Loretta Lynch announced the grant Tuesday in Orlando, where she met with survivors of the shooting attack that killed 49 people. Zlatica Hoke reports.
    Video

    Video How to Print Impossible Shapes with Metal

    3-D printing with metals is rapidly becoming more advanced. As printers become more affordable, the industry is partnering with universities to refine processes for manufacturing previously impossible things. A new 3-D printing lab aims to bring the new technology closer to everyday use. VOA's George Putic reports.
    Video

    Video Big Somali Community in Minnesota Observes Muslim Religious Feast

    Ramadan is widely observed in the north central US state of Minnesota, which a large Muslim community calls home. VOA Somali service reporter Mohmud Masadde files this report from Minneapolis, the state's biggest city.

    Special Report

    Adrift The Invisible African Diaspora