TECH

Nasa Discovers 715 New Alien Planets

27/02/2014 10:32 GMT | Updated 27/02/2014 12:59 GMT

Nasa has announced the confirmed discovery of 715 new alien worlds in deep space.

The so-called "mother lode" of planets outside our solar system ('exoplanets') includes several which appear to be potentially suitable for life.

The enormous distance between ourselves and even the nearest of these worlds means that understanding much about them - including whether they exist at all - is very difficult.

Scientists are not able to look directly through a telescope and see them, but instead study light reaching Earth from distant stars to find small variations, caused by planets moving between the star and Earth.

Using similar techniques - and years of data analysis - scientists using the Kepler Space Telescope have been able to confirm the existence of 715 new worlds around 305 stars, bringing the total found to around 1,800, with hundreds more awaiting confirmation.

The pace of discovery means that it is now likely planets - and perhaps life - and more abundant than previously thought across our galaxy and beyond.

"This is the largest windfall of planets — not exoplanet candidates, mind you, but actually validated exoplanets — that's ever been announced at one time," Douglas Hudgins, exoplanet exploration program scientist at Nasa told the press.

Most of the planets - at least 94% - are smaller than Neptune, meaning it is likely several are rocky like Earth, and so perhaps more likely to host their own forms of life.

Sadly most are also located close to their own stars, meaning they would probably be too hot or radioactive to allow complex life forms to develop. Only four are within the "habitable zone" where liquid water can exist, like on Earth, but that number is low mainly because of the techniques involved which rely on planets passing in front of their sun relative to Earth.

The $600 million Kepler telescope was launched in 2009, and ending its mission last year after it suffered a second wheel failure. But the mountain of data gathered by the craft means that scientists will still find new planets using it for years to come. There are currently more than 3,600 candidate planets, with most likely to be eventually confirmed.