Taking advantage of a total lunar eclipse, Hubble used the Moon as a mirror to study sunlight that had passed through Earth’s atmosphere. As a result, Hubble detected Earth’s own brand of sunscreen – ozone – in our atmosphere. The technique simulates how scientists will search for evidence of life on planets around other stars.
Click here for original story, Hubble uses Earth as proxy for identifying oxygen on potentially habitable exoplanets
Source: ScienceDaily