NASA finds 461 new worlds —some of which may be habitable

The US National Aeronautics and Space Administration's (NASA's) Kepler space observatory has discovered 461 potential new planets, some of which have a chance of being habitable.

 

A report on Space.com said the discovery of the 461 new potential alien planets has jacked up the number of potential alien worlds to 2,740 to date.

 

"Four of the new candidates are 'super-Earths' — planets 1.25 to two times as big as our own — that orbit in their stars' habitable zones, a range of distances where liquid water is possible on a world's surface," it said.

 

It also quoted researchers as saying one of those four is just 1.5 times the size of Earth and circles a sun-like star.

 

Of the 2,470 alien worlds the $600-million Kepler mission found since it started operations in March 2009, 105 have been confirmed, though scientists believe 90 percent may be the "real deal."

 

During the telescope's first 16 months of operation, scientists had previously reported roughly 2,300 other candidate planets.

 

Also, researchers said Kepler's new detections increased the number of stars known to host more than one planet candidate from 365 to 467.

 

"The large number of multi-candidate systems being found by Kepler implies that a substantial fraction of exoplanets reside in flat multi-planet systems. This is consistent with what we know about our own planetary neighborhood," Jack Lissauer, of NASA's Ames Research Center in Moffett Field, Calif., said in a statement.

 

Flagging planets

 

Kepler detects planets by noting the dips in brightness when the planets cross the face of - or transit - their host stars from the instrument's perspective.

 

While early discoveries have been biased toward larger worlds in relatively tight orbits, Kepler may soon find more small planets, and in distant orbits.

 

"The new additions to the catalog reinforce that reality, increasing the number of Earth-size and super-Earth Kepler candidates by 43 percent and 21 percent, respectively," Space.com said.

 

'First true alien Earth'

 

It added the new detections suggest it may only be a matter of time before astronomers detect the first true "alien Earth," or a planet the size of our own in its star's habitable zone.

 

Space.com cited another new Kepler study that showed the Milky Way likely hosts at least 17 billion Earth-size worlds in tight orbits, while many more may circle their stars more distantly. 

 

"The analysis of increasingly longer time periods of Kepler data uncovers smaller planets in longer period orbits — orbital periods similar to Earth's. It is no longer a question of will we find a true Earth analogue, but a question of when," said Steve Howell, Kepler mission project scientist at NASA Ames. — TJD, GMA News