Using the Wide Field Camera 3 (WFC3) instrument onboard the NASA/ESA Hubble Space Telescope, astronomers have detected water vapor in the transmission spectrum of the sub-Neptune exoplanet Gliese 9827d. The water detection in the transit spectrum of Gliese 9827d makes it the first water world candidate with an atmospheric water detection consistent with a water-rich envelope. Image credit: NASA / ESA / Leah Hustak, STScI / Ralf Crawford, STScI. Gliese...
