Ever since the discovery of a new solar system several weeks ago, scientists have been discussing whether planets in the system could contain life. Scientists called the system "TRAPPIST-1". It contains a small sun and seven Earth-sized planets. It is very similar to our own solar system. NASA scientist Michael Gillon said three of the seven TRAPPIST-1 planets receive as much heat from its sun as Venus, Earth and Mars receive from our Sun. He said this provides the right environment for life to exist. TRAPPIST-1 is in a star system called Aquarius. It is nearly 40 light-years away from the Earth. Its sun is smaller than our Sun and has just 1/1000th of its brightness, but that could be enough to support life.
Michael Gillon explained that you could see the other six planets in the sky if you were on one of the TRAPPIST-1 planets. A neighbouring planet could look bigger than our view of our Moon. Mr Gillon said: "If you were on the surface of one of these planets, you would have a wonderful view of the other planets. You wouldn't see them like we see Venus or Mars, like dots of light. You would see them really as we see the Moon. You would see the structures on these worlds." Astronomer Dr Jessie Christiansen said life exists everywhere, "such as bacteria that survives in 130-degree caves, or things at the bottom of the ocean where there's no light". She said it could be possible for life to exist on some of these planets.