Scientists have developed a new method to study reflected light from the Earth that can correctly measure the amount of cloud cover, ocean and vegetation on our planet. The research, reported in the journal Nature, will allow astronomers to eventually study the atmospheric and surface features of planets in other solar systems. Scientists including Dr Michael Sterzik from the European Southern Observatory in Chile used spectroscopy and light polarisation to look for chemical bio-signatures in Earthshine – sunlight reflected by the Earth onto the surface of the Moon and back again.
Light passing through the Earth’s atmosphere contains a tell-tale spectrum revealing the elements within the gas. It is also strongly polarised by scattering from air molecules, aerosols and cloud particles, and by reflection off the oceans and land. By combining these characteristics in a technique called spectropolarimetry, Sterzik and colleagues successfully obtained information about the Earth from reflected light that wouldn’t be achieved by normal spectroscopic readings alone. Read the full article »»»»