News / Science & Technology

    Study: Earth-Like Planets Closer Than Expected

    This artist’s conception shows a habitable planet with two moons orbiting a red dwarf star. (CfA)
    This artist’s conception shows a habitable planet with two moons orbiting a red dwarf star. (CfA)
    VOA News
    Astronomers say there could be as many as 4.5 billion Earth-like planets orbiting stars in the Milky Way galaxy, and the nearest of them could be practically next door, in cosmic terms.

    Scientists at the Harvard-Smithsonian Center for Astrophysics, after analyzing data from NASA's Kepler space telescope, calculated that six percent of the galaxy's 75 billion red dwarf stars have potentially habitable, Earth-sized planets. Red dwarfs -- which are smaller, cooler and much dimmer than our own Sun - are the most common stars in the galaxy, so the closest Earth-like planet could be just 13 light years away, the astronomers conclude in their new study.

    "We thought we would have to search vast distances to find an Earth-like planet," said Harvard astronomer and lead author Courtney Dressing at a Cambridge, Massachusetts, news briefing. "Now we realize another Earth is probably in our own backyard, waiting to be spotted."

    Working from Kepler's 158,000-star catalog, Dressing culled all the red dwarfs and profiled their sizes and temperatures, as well as the number of planet candidates in orbit around them. She narrowed this planet list down to those of just the right size, temperature and distance from their host star to harbor liquid water and, possibly, life as we know it.

    Dressing's analysis found just three planetary candidates that were both warm and approximately Earth-sized. Statistically, that meant that six percent of all red dwarf stars throughout the galaxy should have an Earth-like planet.

    "We now know the rate of occurrence of habitable planets around the most common stars in our galaxy," co-author David Charbonneau, also with the Center for Astrophysics, told reporters. "That rate implies that it will be significantly easier to search for life beyond the solar system than we previously thought."

    Our sun is surrounded by a swarm of red dwarf stars. In fact, about 75 percent of the closest stars are red dwarfs. They are good places to look for Earth-like planets not only because they are so numerous. Their smaller size also makes it easier for astronomers to spot a relatively large Earth-size planet as it transits across the star's disk.

    The Harvard astronomers say locating nearby, Earth-like worlds will require a dedicated small space telescope, or a large network of ground-based telescopes. And they are hopeful that follow-up studies with instruments like the soon-to-be-operational Giant Magellan Telescope in Chile and the James Webb Space Telescope -- due to be launched in 2018 - could eventually tell us whether any warm, transiting planets have an atmosphere and life-friendly chemistry.

    Since red dwarf stars last much longer than Sun-like stars, the astronomers say their analysis raises the possibility that life on one of their Earth-like planets would be much older and more evolved than life on Earth.

    The results of the study are published in The Astrophysical Journal.

    You May Like

    Chechen Suspected in Istanbul Attack, but Questions Remain

    Turkish sources say North Caucasus militants involved in bombing at Ataturk airport, but name of at least one alleged attacker raises doubts

    With Johnson Out, Can a New ‘Margaret Thatcher’ Save Britain?

    Contest to replace David Cameron as Britain’s prime minister started in earnest Thursday with top candidates outlining strategy to deal with Brexit fallout

    US Finds Progress Slow Against Human Trafficking in Africa

    Africa continues to be a major source and destination for human trafficking of all kinds -- from forced labor to sexual slavery, says State Department report

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Clinton Leads Trump, But Many Voters Don't Like Eitheri
    X
    Jim Malone
    June 29, 2016 6:16 PM
    In the U.S. presidential race, most recent polls show Democrat Hillary Clinton with a steady lead over Republican Donald Trump as both presumptive party nominees prepare for their party conventions next month. Trump’s disapproval ratings have risen in some recent surveys, but Clinton also suffers from high negative ratings, suggesting both candidates have a lot of work to do to improve their images before the November election. VOA National correspondent Jim Malone has more from Washington.
    Video

    Video Clinton Leads Trump, But Many Voters Don't Like Either

    In the U.S. presidential race, most recent polls show Democrat Hillary Clinton with a steady lead over Republican Donald Trump as both presumptive party nominees prepare for their party conventions next month. Trump’s disapproval ratings have risen in some recent surveys, but Clinton also suffers from high negative ratings, suggesting both candidates have a lot of work to do to improve their images before the November election. VOA National correspondent Jim Malone has more from Washington.
    Video

    Video Slow Rebuilding Amid Boko Haram Destruction in Nigeria’s Northeast

    Military operations have chased Boko Haram out of towns and cities in Nigeria’s northeast since early last year. But it is only recently that people have begun returning to their homes in Adamawa state, near the border with Cameroon, to try to rebuild their lives. For VOA, Chris Stein traveled to the area and has this report.
    Video

    Video New US Ambassador to Somalia Faces Heavy Challenges

    The new U.S. envoy to Somalia, who was sworn into office Monday, will be the first American ambassador to that nation in 25 years. He will take up his post as Somalia faces a number of crucial issues, including insecurity, an upcoming election, and the potential closure of the Dadaab refugee camp in Kenya. VOA’s Jill Craig asked Somalis living in Kenya’s capital city Nairobi how they feel about the U.S. finally installing a new ambassador.
    Video

    Video At National Zoo, Captivating Animal Sculptures Illustrate Tragedy of Ocean Pollution

    The National Zoo in Washington, D.C., is home to about 1,800 animals, representing 300 species. But throughout the summer, visitors can also see other kinds of creatures there. They are larger-than-life animal sculptures that speak volumes about a global issue — the massive plastic pollution in our oceans. VOA's June Soh takes us to the zoo's special exhibit, called Washed Ashore: Art to Save the Sea.
    Video

    Video Baghdad Bikers Defy War with a Roar

    Baghdad is a city of contradictions. War is a constant. Explosions and kidnappings are part of daily life. But the Iraqi capital remains a thriving city, even if a little beat up. VOA's Sharon Behn reports on how some in Baghdad are defying the stereotype of a nation at war by pursuing a lifestyle known for its iconic symbols of rebellion: motorbikes, leather jackets and roaring engines.
    Video

    Video Melting Pot of Immigrants Working to Restore US Capitol Dome

    The American Iron Works company is one of the firms working to renovate the iconic U.S. Capitol Dome. The company employs immigrants of many different cultural and national backgrounds. VOA’s Arman Tarjimanyan has more.
    Video

    Video Testing Bamboo as Building Material

    For thousands of years various species of bamboo - one of the world's most versatile plants - have been used for diverse purposes ranging from food and medicine to textiles and construction. But its use on a large scale is hampered because it's not manufactured to specific standards but grown in the ground. A University of Pittsburgh professor is on track to changing that. VOA’s George Putic reports.
    Video

    Video Orphanage in Iraqi City Houses Kids Who Lost their Parents to Attacks by IS

    An orphanage in Iraqi Kurdistan has become home to scores of Yazidi children who lost their parents after Islamic State militants took over Sinjar in Iraq’s Nineveh Province in 2014. Iraqi Kurdish forces backed by the U.S. airstrikes have since recaptured Sinjar but the need for the care provided by the orphanage continues. VOA’s Kawa Omar filed this report narrated by Rob Raffaele.
    Video

    Video Re-Opening Old Wounds in a Bullet-Riddled Cultural Landmark

    A cultural landmark before Lebanon’s civil war transformed it into a nest of snipers, Beirut’s ‘Yellow House’ is once again set to play a crucial role in the city.  Built in a neo-Ottoman style in the 1920s, in September it is set to be re-opened as a ‘memory museum’ - its bullet-riddled walls and bunkered positions overlooking the city’s notorious ‘Green Line’ maintained for posterity. John Owens reports from Beirut.
    Video

    Video Brexit Resounds in US Presidential Contest

    Britain’s decision to leave the European Union is resounding in America’s presidential race. As VOA’s Michael Bowman reports, Republican presumptive nominee Donald Trump sees Britain’s move as an affirmation of his campaign’s core messages, while Democrat Hillary Clinton sees the episode as further evidence that Trump is unfit to be president.
    Video

    Video NASA Juno Spacecraft, Nearing Jupiter, to Shed Light on Gas Giant

    After a five-year journey, the spacecraft Juno is nearing its destination, the giant planet Jupiter, where it will enter orbit and start sending data back July 4th. As Mike O'Sullivan reports from Pasadena, California, the craft will pierce the veil of Jupiter's dense cloud cover to reveal its mysteries.
    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.

    Special Report

    Adrift The Invisible African Diaspora