NASA’s Spitzer Space Telescope has detected light emanating from a “super-Earth” beyond our solar system for the first time.
While the planet is not habitable, the detection is a historic step toward the eventual search for signs of life on other planets.
“Spitzer has amazed us yet again,” said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. “The spacecraft is pioneering the study of atmospheres of distant planets and paving the way for NASA’s upcoming James Webb Space Telescope to apply a similar technique on potentially habitable planets.”
The planet, called 55 Cancri e, falls into a class of planets termed super Earths, which are more massive than our home world but lighter than giant planets like Neptune. The planet is about twice as big and eight times as massive as Earth. It orbits a bright star, called 55 Cancri, in a mere 18 hours.
Previously, Spitzer and other telescopes were able to study the planet by analyzing how the light from 55 Cancri changed as the planet passed in front of the star. In the new study, Spitzer measured how much infrared light comes from the planet itself.
The results reveal the planet is likely dark, and its sun-facing side is more than 2,000 Kelvin (3,140 degrees Fahrenheit), hot enough to melt metal.
The new information is consistent with a prior theory that 55 Cancri e is a water world: a rocky core surrounded by a layer of water in a “supercritical” state where it is both liquid and gas, and topped by a blanket of steam: video.