Lava worlds are a potential emerging population of hot super-Earth exoplanets that are on close-in orbits around their host stars, with likely partially molten mantles. Astronomers from the Ohio State University and Southwest Research Institute have found that these sweeping molten oceans have a large influence on the observed properties of hot rocky super-Earths, such as their size and evolutionary path. They found that due to lava’s extremely compressible nature, magma oceans can cause lava worlds without atmospheres to be modestly denser than similarly sized solid planets as well as impact the structure of their mantles, the thick inner layer that surrounds a planet’s core.
“Even so, since these objects are notoriously under-studied, it can be a difficult task to characterize the fundamental workings of lava planets,” said Kiersten Boley, a graduate student at the Ohio State University.
“Lava worlds are very odd, very interesting things and because of the way we detect exoplanets, we’re more biased to finding them.”
One of the most well-known of these mysterious burning worlds is 55 Cancri e, one of five planets orbiting the Sun-like star 55 Cancri A that is located 41 light-years away yet visible to the naked eye in the constellation of Cancer.
“While there are objects in our Solar System, such as Jupiter’s moon Io, that are extremely volcanically active, there aren’t true lava planets in our stretch of the cosmos that scientists can get up close and personal to study,” Boley said.
“However, investigating how the composition of magma oceans contributes to the evolution of other planets, such as for how long they stay molten and for what reasons they eventually cool down, can offer clues into Earth’s own fiery history.”
“When planets initially form, particularly for rocky terrestrial planets, they go through a magma ocean stage as they’re cooling down.”
“So lava worlds can give us some insight into what may have…
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