The planets entitled “Super Lands can be particularly bright for scientists watching them and researchers have already assumed that this striking feature happens because starlight reflects off the vast oceans of lava and glass present on the surface of these exoplanets. However, the reason for so much brilliance may be another.
Hot Super Earths are scaly, rocky exoplanets, smaller than gas giants, located close to their stars and exhibiting a relatively fine atmosphere. However, they are huge compared to our Earth, being two to ten times larger.
In a study published in the scientific journal Astrophysical Journal, scientists from the Massachusetts Institute of Technology (MIT, the acronym in English) suggest that the hot Super Earths are so bright thanks to the reflective clouds that form in their atmospheres rich in metals.
Simulation of the surface and atmosphere of a hot Super Earth. Image: iStock
Although the lava and glass oceans hypothesis was widely accepted, there was no evidence to support it. It was then that MIT researchers built miniatures of hot Super Earths by melting rocks in the laboratory to calculate how bright the lava and glass would look. The result was scalding balls that were proportionally less brilliant than expected compared to the glow emitted by real exoplanets.
"We are not 100% sure of what these planets are made of, so we are narrowing the parameter space and guiding future studies for all these other potential options," explained Zahra Essack, an MIT student who worked on the research.
The study conducted by MIT scientists also did not provide evidence for the existence of metal-rich clouds, but it did suggest that there must be something else behind the abnormal luminosity of the hot Super Earths - and the atmosphere seems to be a good way to find out why. .
"We still have a lot to understand about these lava ocean planets," said Essack. "We think of them only as shiny rock balls, but these planets can have complex systems of very exotic surface and atmospheric processes, and not something we've seen before," he added.