News / Science & Technology

Gassy Exoplanet has Earth-like Mass

KOI-314c, shown in this artist's conception, is the lightest planet to have both its mass and physical size measured. (Harvard-Smithsonian Center for Astrophysics)
KOI-314c, shown in this artist's conception, is the lightest planet to have both its mass and physical size measured. (Harvard-Smithsonian Center for Astrophysics)

Related Articles

Astronomers Discover Earth-sized 'Lava Planet'

Life on the planet is unlikely as surface temperatures rang from 2,000 to 2,800 Celsius

Study Finds Billions of Earth-like Planets

Until now it was not known how common potentially habitable planets existed near sun-like stars, researchers say

Astronomers Spot Water on Five Exoplanets

NASA says the planets are likely 'hot Jupiters'
VOA News
Astronomers have discovered what they’re saying is the first planet outside our solar system, or exoplanet, with the same mass as Earth. But although its weight is similar to Earth, the planet is 60 percent larger in diameter.

KOI-314c, which likely has a thick gaseous atmosphere, orbits a dim red dwarf star and is about 200 light-years away. The astronomers said it circles its star every 23 days and that its temperature is around 220 degrees Fahrenheit, too hot for life as we know it.

"This planet might have the same mass as Earth, but it is certainly not Earth-like," says David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA), lead author of the discovery. "It proves that there is no clear dividing line between rocky worlds like Earth and fluffier planets like water worlds or gas giants."

KOI-314c is only 30 percent denser than water. This suggests that the planet is enveloped by a significant atmosphere of hydrogen and helium hundreds of miles thick. It might have begun life as a mini-Neptune and lost some of its atmospheric gases over time, boiled off by the intense radiation of its star.

Weighing such a small planet was a challenge. Conventionally, astronomers measure the mass of an exoplanet by measuring the tiny wobbles of the parent star induced by the planet's gravity. But this method is extremely difficult for a planet with Earth's mass. The previous record holder for a planet with a measured mass (Kepler-78b) weighed 70 percent more than Earth.

To weigh KOI-314c, the team relied on a different technique known as transit timing variations (TTV). This method can only be used when more than one planet orbits a star. The two planets tug on each other, slightly changing the times that they transit their star.

Using this technique, the astronomers actually found two planets. The second planet in the system, KOI-314b, is about the same size as KOI-314c but significantly denser, weighing about 4 times as much as Earth. It orbits the star every 13 days.

The discovery was serendipitous, as the team was looking for exomoons, not exoplanets.

"When we noticed this planet showed transit timing variations, the signature was clearly due to the other planet in the system and not a moon. At first we were disappointed it wasn't a moon but then we soon realized it was an extraordinary measurement," said Kipping.

Kipping presented this discovery, which was based on data from NASA’s Kepler spacecraft, at the 223rd meeting of the American Astronomical Society.

You May Like

Is Air Travel Safe?

Aviation expert says despite tragic losses of Malaysian Airlines flights 370 and 17, industry experienced lowest fatality rate in recorded history last year More

Multimedia 100 Days Later, Nigerian Girls Still Held

Activists holding rallies in Nigeria and several other countries to mark 100th day of captivity for more than 200 schoolgirls being held by Boko Haram More

Chocolate Too Bitter? Swap Sugar for Mushrooms

US food technology company develops fermentation process using mushrooms to reduce bitterness in cocoa beans, believes it will cut sugar content in candy 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.
US Carriers Suspend Travel to Israeli
X
Carolyn Presutti
July 23, 2014 1:21 AM
The United States is prohibiting American carriers from flying to Israel's airport in Tel Aviv for 24 hours, because of rising violence between Israel and Hamas militants. The action was announced on Tuesday, after a rocket fired by Hamas militants in the Gaza Strip landed near the airport. As VOA's Carolyn Presutti tells us, international officials soon may have to determine which combat zones are too dangerous for commercial flights.
Video

Video US Carriers Suspend Travel to Israel

The United States is prohibiting American carriers from flying to Israel's airport in Tel Aviv for 24 hours, because of rising violence between Israel and Hamas militants. The action was announced on Tuesday, after a rocket fired by Hamas militants in the Gaza Strip landed near the airport. As VOA's Carolyn Presutti tells us, international officials soon may have to determine which combat zones are too dangerous for commercial flights.
Video

Video NASA Focuses on Earth-Like Planets

For decades, looking for life elsewhere in the universe meant listening for signals that could be from distant civilizations. But recent breakthroughs in space technology refocused some of that effort toward finding planets that may harbor life, even in its primitive form. VOA’s George Putic reports on a recent panel discussion at NASA’s headquarters, in Washington.
Video

Video IAEA: Iran Turns its Enriched Uranium Into Less Harmful Form

Iran has converted its stockpiles of enriched uranium into a less dangerous form that is more difficult to use for nuclear weapons, according to the United Nations’ Atomic Energy Agency. The move complies with an interim deal reached with Western powers on Iran's nuclear program last year, in exchange for easing of sanctions. Henry Ridgwell reports for VOA from London.
Video

Video Relic of Saint Draws Catholics Worried About Immigration Issue

A Roman Catholic saint who is a figure of devotion for those crossing the border into the United States is attracting believers concerned about the plight of undocumented immigrants. Mike O'Sullivan reports from Los Angeles, where a relic of Saint Toribio has drawn thousands to local churches.
Video

Video US Awards Medal of Honor for Heroics in Bloodiest of Afghan Battles

U.S. combat troops are withdrawing from Afghanistan, on pace to leave the country by the end of this year. But on Monday, U.S. President Barack Obama took time to honor a soldier whose actions while under fire in Afghanistan earned him the Medal of Honor. VOA's Jeff Seldin has more from the Pentagon.
Video

Video Ukraine Rebels Surrender MH17 Black Boxes

After days of negotiations, a senior separatist leader handed over two black boxes from an airliner downed over eastern Ukraine to Malaysian experts early Tuesday. While on Monday, the U.N. Security Council unanimously demanded that armed groups controlling the crash site allow safe and unrestricted access to the wreckage.
Video

Video In Cambodia, HIV Diagnosis Brings Deadly Shame

Although HIV/AIDS is now a treatable condition, a positive diagnosis is still a life altering experience. In Cambodia, people living with HIV are often disowned by friends, family and the community. This humiliation can be unbearable. We bring you one Cambodian woman’s struggle to overcome a life tragedy and her own HIV positive diagnosis.
Video

Video Nature of Space Exploration Enters New Age

Forty-five years ago this month, the first humans walked on the moon. It was during an era of the space race between the United States and the Soviet Union. World politics have changed since then and -- as Elizabeth Lee reports -- so has the nature of space exploration.

AppleAndroid