World News

Friday 29 August 2014

17 billion planets 'like Earth'

Published 07/01/2013 | 20:05

  • Share
The Milky Way galaxy is home to at least 17 billion planets similar in size to Earth, a new estimate suggests

The Milky Way galaxy is home to at least 17 billion planets similar in size to Earth, a new estimate suggests.

  • Share
  • Go To

Not all are potentially habitable, but the huge number is a starting point in the search for worlds like our own.

Scientists have yet to find a twin Earth - one that is not only the right size but also located in a zone that is not too hot and not too cold where water might exist in liquid form.

Two independent groups came up with the new estimate after a fresh analysis of data gathered by Nasa's Kepler spacecraft, launched in 2009 to track down other Earths. The craft spots a planet when it passes in front of the planet's star.

One team led by Francois Fressin of the Harvard-Smithsonian Centre for Astrophysics estimated at least one in six stars has an Earth-size planet orbiting it.

Using a different method, researchers at the University of California, Berkeley and University of Hawaii determined that 17% of stars host planets that are one to two times the diameter of Earth.

The findings were presented at the American Astronomical Society.

Press Association

Read More

Editors Choice

Also in this section