Hubble uses Earth as proxy for identifying oxygen on potentially habitable exoplanets

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.

from Top Technology News -- ScienceDaily https://ift.tt/2PxxAxD