Lava oceans may not explain the brightness of some hot super-Earths
Arguably some of the weirdest, most extreme planets among the more than 4,000 exoplanets discovered to date are the hot super-Earths — rocky, flaming-hot worlds that zing so precariously close to their host stars that some of their surfaces are likely melted seas of molten lava. These fiery worlds, about the size of Earth, are known more evocatively as “lava-ocean planets,” and scientists have observed that a handful of these hot super-Earths are unusually bright, and in fact brighter than our own brilliant blue planet. Exactly why these far-off fireballs are so bright is unclear, but new experimental evidence by scientists at MIT shows that the unexpected glow from these worlds is likely not due to either molten lava or cooled glass (i.e. rapidly solidified lava) on their surfaces. The researchers came to this conclusion after interrogating the problem in a refreshingly direct way: melting rocks in a furnace and measuring the brightness...