25 Jun 2015

Astronomers from the University of Geneva (UNIGE) and members of the NCCR -for National Centre of Competence in Research- PlanetS disco- vered an immense cloud of hydrogen escaping from an exoplanet the size of Neptune.
This phenomenon generates like a tail or a head of hair giving it the appearance of a giant comet. Already observed in some very large and very hot exoplanets, this phenomenon is viewed for the first time with such a magnitude. The cloud might explain the formation of some hot and rocky super-Earths. It would also be an indicator for detec- ting extrasolar oceans. Finally, it would be used to envisage the future of our atmosphere. These results are published in the latest edition of the journal Nature.

Image: Planète GJ 436b, artist's impression.