This animation shows two Earth-sized planets passing in front of their parent red dwarf star. The Hubble Space Telescope was used to spectroscopically search for evidence of extended atmospheres around these planets, but no evidence was found. This leaves open the possibility the planets have thinner, denser atmospheres like Earth's. Researchers think that at least one of the planets, and possibly both, may be within the star's habitable zone, where moderate temperatures could allow for liquid water to exist on the surface.

NASA, ESA, and G. Bacon (STScI)

Publication: July 20, 2016