【明報專訊】SCIENTIFIC study shows that a planet eight times the size of Earth has temperatures that could sustain life. It is outside our solar system thus is an exoplanet (系外行星). Also, for the first time, water vapour has been detected in the atmosphere of an exoplanet. Theoretically speaking, there may already be life on this planet. But it could be very different from that on Earth since creatures would need to overcome gravity that is stronger than our planet's.