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

Multimedia Social Media Documenting, Not Driving, Hong Kong Protests

Unlike in Arab Spring uprisings, pro-democracy protesters in Hong Kong aren't relying on Twitter and Facebook to organize, but social media still plays a role More

Analysis: Occupy Central Not Exactly Hong Kong’s Tiananmen

VOA's former Hong Kong, Beijing correspondent compares and contrasts 1989 Tiananmen Square protest with what is now happening in Hong Kong More

Bambari Hospital a Lone Place of Help in Violence-Plagued CAR

Only establishment still functioning in CAR's second city is main hospital More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
The Legacy of Jimmy Carter: The Preacher from Plainsi
X
October 01, 2014 10:45 AM
It is common in the United States to see tourists flock to sites associated with America's presidents. Some are privately owned and others are run by the National Park Service or the National Archives -- but most have helped draw business and people into the towns and cities where they are located. As VOA’s Kane Farabaugh reports, there is one particular presidential hometown that is unique in what it has to offer those who make the trip.
Video

Video The Legacy of Jimmy Carter: The Preacher from Plains

It is common in the United States to see tourists flock to sites associated with America's presidents. Some are privately owned and others are run by the National Park Service or the National Archives -- but most have helped draw business and people into the towns and cities where they are located. As VOA’s Kane Farabaugh reports, there is one particular presidential hometown that is unique in what it has to offer those who make the trip.
Video

Video Hong Kong Protests Draw New Supporters on National Holiday

On the 65th anniversary of the founding of Communist China, Hong Kong protesters are hoping to stage the largest pro-democracy demonstration since the 1989 Tiananmen protests. VOA's Brian Padden visited one of the protest sites mid-day, when the atmosphere was calm and where the supporters were enthusiastic about joining what they are calling the umbrella revolution.
Video

Video India's PM Continues First US Visit

India's prime minister is on his first visit to Washington, to strengthen political and economic ties between the world's oldest and the world biggest democracies. He came to the U.S. capital from New York, the first stop on his five-day visit to the country that denied him an entry visa in the past. From Washington, Zlatica Hoke reports Modi seemed most focused on attracting foreign investment and trade to increase job opportunities for his people.
Video

Video Malaysia Struggles to Stop People Joining Jihad

Malaysian authorities say militant groups like the so-called "Islamic State" have used social media to entice at least three dozen Malaysian Muslims to fight in what they call "jihad" in Syria and Iraq. As Mahi Ramkrishnan reports from Kuala Lumpur, counterterrorism police are deeply worried about what could happen when these militants return home.
Video

Video Could US Have Done More to Stop Rise of Islamic State?

President Obama says airstrikes against Islamic State militants in Syria will likely continue for some time because, in his words, "there is a cancer that has grown for too long." So what if President Obama had acted sooner in Syria to arm more-moderate opponents of both the Islamic State and the Syrian government? VOA State Department Correspondent Scott Stearns reports from the United Nations.
Video

Video Treasure Hunters Seek 'Hidden Treasure' in Central Kenya

Could a cave in a small village in central Kenya be the site of buried treasure? A rumor of riches, left behind by colonialists, has some residents dreaming of wealth, while others see it as a dangerous hoax. VOA's Gabe Joselow has the story.
Video

Video Ebola Patients Find No Treatment at Sierra Leone Holding Center

At a holding facility in Makeni, central Sierra Leone, dozens of sick people sit on the floor in an empty university building. They wait in filthy conditions. It's a 16-hour drive by ambulance to Kailahun Ebola treatment center. Adam Bailes was there and reports on what he says are some of the worst situations he has seen since the beginning of this Ebola outbreak. And he says it appears case numbers may already be far worse than authorities acknowledge.
Video

Video Identifying Bodies Found in Texas Border Region

Thousands of immigrants have died after crossing the border from Mexico into remote areas of the southwestern United States in recent years. Local officials in south Texas alone have found hundreds of unidentified bodies and buried them in mass graves in local cemeteries. Now an anthropologist and her students at Baylor University have been exhuming bodies and looking for clues to identify them. VOA’s Greg Flakus has more from Waco, Texas.
Colonel Steve ‘Spiros’ Pisanos left Greece and came to the U.S. to learn to fly. He flew fighters for the Allies in World War II, narrowly escaping death multiple times.Colonel Steve ‘Spiros’ Pisanos left Greece and came to the U.S. to learn to fly. He flew fighters for the Allies in World War II, narrowly escaping death multiple times.

AppleAndroid