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

US Gives Malaysia Questionable Upgrade in Human Trafficking Ranks

Malaysia’s upgrade seen as removing barrier to country’s participation in the US-led 12-nation Trans-Pacific Partnership More

Turkey, US Try to Establish Buffer Despite Differences

Coalition airstrikes in proposed zone would aim to drive out Islamic extremists, allowing targeted area to come under sway of anti-Assad rebels More

Video US: Millions Exploited by Vast Fortunes of Human Trafficking

State Department's annual report calls exploitation 'modern slavery,' brutalizing girls, women into prostitution and forcing men, women and children into low-wage jobs across the globe More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
US Calls Fight Against Human Trafficking a Must Wini
X
July 28, 2015 12:21 AM
The United States is promising not to give up its fight against what Secretary of State John Kerry calls the “scourge” of modern slavery. Officials released the country’s annual human trafficking report Monday – a report that’s being met with some criticism. VOA’s National Security correspondent Jeff Seldin has more from the State Department.
Video

Video US Calls Fight Against Human Trafficking a Must Win

The United States is promising not to give up its fight against what Secretary of State John Kerry calls the “scourge” of modern slavery. Officials released the country’s annual human trafficking report Monday – a report that’s being met with some criticism. VOA’s National Security correspondent Jeff Seldin has more from the State Department.
Video

Video Iran Nuclear Pact Wins Few New US Congressional Backers

Later this week, President Barack Obama returns from a trip to Africa to confront a U.S. Congress roiled by the nuclear accord with Iran, an agreement that has received the blessing of the U.N. Security Council. Days of intensive lobbying and testimony by top administration officials have won few new congressional supporters of the pact. VOA’s Michael Bowman reports.
Video

Video Washington DC Underground Streetcar Station to Become Arts Venue

Abandoned more than 50 years ago, the underground streetcar station in Washington D.C.’s historic DuPont Circle district is about to be reborn. The plan calls for turning the spacious underground platforms - once meant to be a transportation hub, - into a unique space for art exhibitions, presentations, concerts and even a film set. Roman Mamonov has more from beneath the streets of the U.S. capital. Joy Wagner narrates his report.
Video

Video Obama Encourages Kenya to Fix Cultures of Corruption, Discrimination

President Barack Obama bid farewell to Kenya Sunday with a major speech at as stadium outside the capital Nairobi where he called on Kenyans to change the cultures of corruption and discrimination that can hold society back. VOA East Africa Correspondent Gabe Joselow has the story.
Video

Video Europe’s Twin Crises Collide in Greece as Migrant Numbers Soar

Greece has replaced Italy as the main gateway for migrants into Europe, with more than 100,000 arrivals in the first six months of 2015. Many want to move further into Europe and escape Greece’s economic crisis, but they face widespread dangers on the journey overland through the Balkans. VOA's Henry Ridgwell reports.
Video

Video Stink Intensifies as Lebanon’s Trash Crisis Continues

After the closure of a major rubbish dump a week ago, the streets of Beirut are filling up with trash. Having failed to draw up a plan B, politicians are struggling to deal with the problem. John Owens has more for VOA from Beirut.
Video

Video Paris Rolls Out Blueprint to Fight Climate Change

A U.N. climate conference in December aims to produce an ambitious agreement to fight heat-trapping greenhouse gases. But many local governments are not waiting, and have drafted their own climate action plans. That’s the case with Paris — which is getting special attention, since it’s hosting the climate summit. Lisa Bryant takes a look for VOA at the transformation of the French capital into an eco-city.
Video

Video Racially Diverse Spider-Man Takes Center Stage

Whether it’s in a comic book or on the big screen, fans have always known the man behind the Spider-Man mask as Peter Parker. But that is changing, at least in the comic book world. Marvel Comics announced that a character called Miles Morales will replace Peter Parker as Spider-Man in a new comic book series. He is half Latino, half African American, and he is quite popular among comic book fans. Correspondent Elizabeth Lee reports from Los Angeles.
Video

Video California Towns Welcome Special Olympics Athletes

Cities and towns in Southern California are greeting thousands of athletes who are arriving for Special Olympics, a competition for people with intellectual disabilities. The games will run from July 25th through August 2nd. VOA's Mike O'Sullivan reports from Pasadena, California, where athletes from Namibia, Singapore and Tanzania got a rousing welcome from local residents.
Video

Video Critics of Japan Defense Policy Focus on Okinawa

In Okinawa, many locals have long complained that Tokyo places an unfair burden on the tiny island by locating most of Japan's U.S. military bases there. As Japan's government moves toward strengthening and expanding the country's defense policies, opponents of those plans are joining local protesters in Okinawa, voicing concern about where the country is headed. VOA’s Brian Padden reports from Okinawa.
Video

Video IS Uses Chemical Weapons in Syrian Attack

Islamic State militants have added a new weapon in their arsenal of fear: chemical weapons. VOA Kurdish service reporter Zana Omer was on the scene within hours of a recent attack in Hasakah, Syria, and has details of the subsequent investigation, in this report narrated by Miguel Amaya.
Video

Video Historic Symbol Is Theme of Vibrant New Show

A new exhibit in Washington is paying tribute to the American flag with a wide and eclectic selection of artwork that uses the historic symbol as its central theme. VOA’s Julie Taboh was at the DC Chamber of Commerce for the show’s opening.
Video

Video Hoverbike Flying Toward Reality

Another long-standing dream of many technological inventors is quickly approaching reality: U.S.- and British-based firms are cooperating in the development of an individual flying platform they call a hoverbike. They say it may revolutionize the concept of flying, including in the U.S. military. VOA’s George Putic reports.
Video

Video As Japan Expands Defense Role, Protests Follow

The Japanese government is moving forward with a controversial security bill that would authorize the military to fight abroad for the first time since World War II. Leaders say it is critical to defend against rising threats from China and North Korea. VOA’s Brian Padden reports from Japan on the big changes ahead, and the opposition they are drawing.
Video

Video Replacing Poppies with Coffee in Myanmar

The remote mountains of Myanmar’s Shan state are home to the second-largest opium-producing region in the world. After a drop during the 2000s, production surged in the past eight years to feed an increasing demand for heroin in China. But farmers are now making less on the crop, and the U.N. is hoping many will make the switch to growing coffee. Daniel de Carteret reports for VOA from Taunggyi.

VOA Blogs