News24

2 Earth-size planets spotted

2011-12-20 22:25

New York - Scientists have found two Earth-sized planets orbiting a star outside the solar system, an encouraging sign for prospects of finding life elsewhere.

The discovery shows that such planets exist and that they can be detected, said Francois Fressin of the Harvard-Smithsonian Centre for Astrophysics.

They're the smallest planets found so far that orbit a star resembling our sun.

Scientists are seeking Earth-sized planets as potential homes for extraterrestrial life, said Fressin, who reports the new findings in a paper published online on Tuesday by the journal Nature.

One planet's diameter is only 3% larger than Earth's, while the other's diameter is about nine-tenths that of Earth. They appear to be rocky, like our planet.

Life-friendly

But they are too hot to contain life as we know it, with calculated temperatures of about 815°C and 426°C, he said.

Any life found on another plant may not be intelligent; it could be bacteria or mould or some completely unknown form.

Since it was launched in 2009, Nasa's planet-hunting Kepler telescope has found evidence of dozens of possible Earth-sized planets.

But Fressin's report is the first to provide confirmation, said Alan Boss of the Carnegie Institution for Science in Washington. He's a member of the Kepler science team but not an author of the paper.

The researchers ruled out a possible alternative explanation for the signals that initially indicated the planets were orbiting the star Kepler-20. The star is 950 light-years from Earth in the direction of the constellation Lyra.

The planets are called Kepler-20e and Kepler-20f.

Earlier this month, scientists said they had found a planet around another distant star with a life-friendly surface temperature of about 22°C. But it was too big to suggest life on its surface.

At 2.4 times the size of Earth, it could be more like the gas-and-liquid Neptune with only a rocky core and mostly ocean, scientists said.

Comments
  • lawrence.ostle - 2011-12-20 23:46

    " Any life found on another plant (SIC) may not be intelligent; it could be bacteria or mould or some completely unknown form " ...so the ANC have offices on other planets now?

  • Zion - 2011-12-21 07:49

    Scientists are investigating if the planets can support life. Moulds and fungi are presented as life but who the hell will want to live in a hell hole where temperatures are 815 and 426 degrees respectively. If the temperature is the deciding factor then why waste our time. How far are these planets from earth and how long to get there?

      anthony.weineck - 2011-12-21 08:05

      No one is proposing that we live there. We're trying to find out whether anything else does. I guess that might seem boring to you, but curiosity is one of the defining characteristics of human nature. Also, if you actually read the article, you could answer your own question: the planets are roughly 950 light-years from earth. Yes it would take a long time to go there, but that doesn't mean we can't learn anything from it.

      mbossenger - 2011-12-21 10:55

      Zion - way to miss the point of the article

      UweK - 2011-12-21 17:02

      as per the article approx 950 light years. the distance light travels in one year x 950. Thats pretty damn far. Light travels just under 300 000 km (yes three hundred thousand) per second. 950 x 365 x 24 x 60 x 60 x 300000 = 29959200000 km away. years days hours minutes seconds speed = total distance. It is ASTRONOMICALLY far :)

  • Jacques - 2011-12-21 17:42

    uwek, you made a booboo. forgot to multiply with 300 000(distance traveled in 1 second), thus making it 8 987 501 984 750 000 kms !!!!!

      allcoveredinNinjas - 2011-12-22 08:52

      Just round the corner !

  • Zion - 2011-12-21 18:15

    I concur I made a mistake. I did not finish reading the article. So let us crunch some numbers: Some weeks ago I calculated the time it would take to reach a planet (or star) 20 light years away from Earth: Conditions are the ship would accelerate to half the speed of light then cruise at V2 to the planet a= 4x earth gravity being about 40m/sec/sec. What will T be? If the calculation is done then it will be a very long time. Under the conditions given in the article the time to travel 950 light years will be astronomical. I personally find the figures given as probably exaggerated. Have a Happy Christmas.

      Shannon - 2011-12-21 18:28

      Whoa! lay off the eggnog!

      Zion - 2011-12-22 10:44

      Shannon, suggest you lay off the stupidity and ignorance. Must be hard to be a cretin.

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