The Hubble Telescope looked at Earth during an eclipse. We will search for life on other planets in a similar way
During a total lunar eclipse, astronomers using the Hubble Space Telescope discovered ozone in the Earth’s atmosphere. Using the same method, they would be able to search for life on Earth-like planets orbiting other stars. These were the first observations of a total lunar eclipse with a space telescope, and the first observations of an ultraviolet eclipse. To prepare for the study of exoplanets with much larger, emerging telescopes, astronomers decided to carry out a few experiments much closer, focusing their observations on the only known planet with life to date: Earth. The ideal alignment of the Earth, the Sun and the Moon during a total lunar eclipse allows you to study the Earth as you would study rocky planets passing in front of their host star. A diagram showing the geometry of the lunar eclipse. Source: ESA / Hubble, M. Kornmesser In this case, Hubble was not looking directly at Earth. Instead, astronomers used the Moon as a mirror to reflect the Sun’s rays as th...