Gliese 1214b is a so-called mini-Neptune, a smaller, denser version of Neptune that consists of a rocky core surrounded by a thick blanket of gas.
Gliese 1214b is located approximately 52 light-years away in the constellation of Ophiuchus.
This exoplanet orbits a red dwarf star, Gliese 1214, every 38 hours at a distance of 1.3 million miles.
Discovered in 2009 by the MEarth Project, Gliese 1214b is about 2.7 times Earth’s diameter and weighs almost seven times as much.
And while the planet, also known as GJ 1214b, is too hot to harbor liquid-water oceans, water in vaporized form still could be a major part of its atmosphere.
“The planet is totally blanketed by some sort of haze or cloud layer,” said University of Maryland astronomer Eliza Kempton.
“The atmosphere just remained totally hidden from us until this observation.”
“If indeed water-rich, the planet could have been a water world, with large amounts of watery and icy material at the time of its formation.”
To penetrate such a thick barrier, Dr. Kempton and colleagues took a chance on a novel approach.
In addition to making the standard observation, they tracked Gliese 1214b through nearly its entire orbit around its parent star.
Using Webb’s Mid-Infrared Instrument (MIRI), they were able to create a kind of heat map of the planet.
The heat map revealed — just before the planet’s orbit carried it behind the star, and as it emerged on the other side — both its day and night sides, unveiling details of the atmosphere’s composition.
“The ability to get a full orbit was really critical to understand how the planet distributes heat from the day side to the night side,” Dr. Kempton said.
“There’s a lot of contrast between day and night. The night side is colder than the day side.”
“In fact, the temperatures shifted from 279 to 165 degrees Celsius (535 to 326 degrees Fahrenheit).”
Such a big shift is only possible in an atmosphere made up of heavier molecules, such as…
Read the full article here