Researchers revealed on Wednesday the discovery of a thick atmosphere shrouding a planet twice the size of Earth, located in a nearby solar system.
This so-called super-Earth, known as 55 Cancri e, is one of the few rocky planets outside our solar system known to have a substantial atmosphere. The atmospheric blanket consists of carbon dioxide and carbon monoxide, although the exact proportions remain unclear. In contrast, Earth’s atmosphere is a mixture of nitrogen, oxygen, argon, and other gases.
“It’s probably the firmest evidence yet that this planet has an atmosphere,” said Ian Crossfield, an astronomer at the University of Kansas who specializes in exoplanets and was not involved in the study. The groundbreaking research was published in the prestigious journal Nature.
What is a Super-Earth ?
“Super-Earth” refers to a planet larger than Earth but smaller than Neptune. 55 Cancri e boasts scorching temperatures reaching a staggering 4,200 degrees Fahrenheit (2,300 degrees Celsius), making it highly unlikely to harbor life as we know it.
However, scientists believe this discovery holds exciting implications. It suggests that other rocky planets with thick atmospheres could exist and potentially offer more hospitable conditions for life.
The exoplanet, located 41 light-years away, is eight times heavier than Earth. It orbits its star, Copernicus, so closely that it experiences permanent day and night sides. Its surface is a dramatic vista of molten magma oceans.
To decipher the composition of its atmosphere, researchers meticulously analyzed observations from the Webb Space Telescope, focusing on data captured before and after the planet passed behind its star. By separating the light emitted by the planet from that of its star, they calculated the planet’s temperature. The findings revealed a more even distribution of heat across the planet’s surface – a telltale sign of an atmosphere’s influence.
Scientists speculate that gases released from its magma oceans may play a crucial role in maintaining its atmospheric stability. Further exploration of this super-Earth could unveil valuable insights into the early evolution of planets with magma oceans, such as Earth and Mars, which have since cooled.
“It’s a rare window,” said Renyu Hu, a planetary scientist at NASA’s Jet Propulsion Laboratory and a member of the research team. “We can look into this early phase of planet evolution.”