Free Astronomy Magazine September-October 2015

46 SEPTEMBER-OCTOBER 2015 SPACE CHRONICLES this feature before around more massive exoplanets). It may offer clues as to how hot super-Earths — massive, hot versions of Earth — are born around other stars. "This cloud of hydrogen is very spec- tacular!" says David Ehrenreich of the Observatory of the University of Atmosphere stripped from Neptune-sized exoplanet by NASA A stronomers using the NASA/ ESA Hubble Space Telescope have discovered an immense cloud of hydrogen dispersing from a warm, Neptune-sized planet orbi- ting a nearby star. The enormous gaseous tail of the planet is about 50 times the size of the parent star. A phenomenon this large has never before been seen around such a small exoplanet (Hubble observed Geneva in Switzerland, lead author of the study. "Although the evap- oration rate doesn't threaten the planet right now, we know that the star, a faint red dwarf, was more