Elijah Williams
A thick atmosphere has been detected around a planet that is twice the size of Earth in a nearby solar system, researchers reported Wednesday.
The so-called super Earth – known as 55 Cancri e – is among the few rocky planets outside our solar system with a significant atmosphere, shrouded in a blanket of carbon dioxide and carbon monoxide. The exact values are unclear. Earth’s atmosphere is a mixture of nitrogen, oxygen, argon and other gases.
“It’s probably the firmest evidence that this planet has an atmosphere,” said Ian Crossfield, an astronomer at the University of Kansas who studies exoplanets and was not involved in the research.
The research was published in the journal Nature.
Super Earth refers to the size of a planet – larger than Earth but smaller than Neptune. The boiling temperatures on this planet – which can get so hot like 4,200 degrees Fahrenheit – means it is unlikely to host life.
NASA/JPL-Caltech via AP
Instead, scientists say the discovery is a promising sign that there may be other rocky planets with thick atmospheres that may be more hospitable.
The exoplanet 41 light-years away is eight times heavier than Earth and circles its star Copernicus so closely that it has permanent day and night sides. One light year is almost 6 trillion miles (9.7 trillion kilometers). Its surface is encrusted by oceans of magma.
To identify the composition of its atmosphere, researchers studied observations from the Webb Space Telescope before and after the planet passed behind its star.
They separated the light emitted by the planet and its star and used the data to calculate the planet’s temperature. There is evidence that the planet’s heat was being distributed more evenly across its surface – a festive trick that atmospheres are known for.
Gases from its magma oceans can play a key role in maintaining the stability of its atmosphere. Exploring this super Earth could also provide clues about how Earth and Mars may have first evolved with magma oceans that have since cooled, scientists say.
“It’s a rare window,” said Renyu Hu, a planetary scientist at NASA’s Jet Propulsion Laboratory who was part of the research. “We can analyze this early phase of the planet’s evolution.”
55 Cancri e is not the first super-Earth planet that scientists have detected in recent years. An international team of scientists said in 2022 that there were found two such planets, just 100 light years from Earth. Both planets circle a red dwarf star, and one of them, known as LP 890-9c, may even be habitable.
In August 2022, NASA scientists discovered a super Earth this could be a “water world,” making it also a candidate for sustaining life. Researchers have not yet confirmed how much water there is on the planet, known as TOI-1452 b. NASA said at the time that the James Webb Space Telescope would be used to further study the planet.
“As soon as we can, we will set aside time at Webb to observe this strange and wonderful world,” researcher René Doyon said at the time.
