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