... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... This shows the Sun, Moon and Earth (not to scale) together with the . ... They have tested the technique on the Earthshine, the light reflected from the Earth by the Moon, and showed that it can reveal the presence of life in our planet. ... This technique uses the fact that the light reflected from the planet is polarised, whereas that emitted by the star is not. ... Polarised light can tell us about the reflecting surface...
... It s because some sunlight bounced off the Earth and dimly lit the side of the Moon that is facing away from the Sun. ... Recently, astronomers used earthshine to help in the search for aliens. Signs of life can be found in the quantities of particular gases in a planet s atmosphere, such as oxygen, ozone, methane and carbon dioxide. And astronomers can work out what gases are in a planet s atmosphere by studying the light that bounces off them their planetshine . ...