Unexpectedly primitive atmosphere found around distant 'warm Neptune'

(University of Maryland) A new study led by NASA with contributions from the University of Maryland reveals that the distant planet HAT-P-26b has a primitive atmosphere composed almost entirely of hydrogen and helium. Located about 437 light years away from Earth, HAT-P-26b orbits a star roughly twice as old as the sun. The analysis is one of the most detailed studies to date of a 'warm Neptune,' a planet that is Neptune-sized and orbits close to its star.