NASA’s infrared Spitzer Space Telescope spotted light from the alien planet 55 Cancri e, which orbits a star 41 light-years from Earth.
A year on the extrasolar planet lasts just 18 hours. The planet 55 Cancri e was first discovered in 2004 and is not a habitable world. Instead, it is known as a super-Earth because of its size: The world is about twice the width of Earth and is super-dense, with about eight times the mass of Earth. But until now, scientists have never managed to detect the infrared light from the super-Earth world. Spitzer first detected infrared light from an alien planet in 2005. But that world was “hot Jupiter,” a gas giant planet much larger than 55 Cancri e that orbited extremely close to its parent star. The new Spitzer observations revealed that the star-facing side of 55 Cancri e is extremely hot, with temperatures reaching up to 3,140 degrees Fahrenheit (1,726 degrees Celsius). The planet is likely a dark world that lacks the substantial atmosphere needed to warm its nighttime side. Past observations of the planet by the Spitzer Space Telescope have suggested that one-fifth of 55 Cancri e is made up of lighter elements, including water. But the extreme temperatures and pressures on 55 Cancri e would create what scientists call a “supercritical fluid” state. Supercritical fluids can be imagined as a gas in a liquid state, which can occur under extreme pressures and temperatures. On Earth, water can become a supercritical fluid inside some steam engines. The previous studies of 55 Cancri e were performed by analyzing how the light from its parent star changed as the planet passed in front of it, a technique known as the “transit method.” In the new study, astronomers used the Spitzer Space Telescope to determine the infrared light from 55 Cancri e itself. Spitzer’s new look at 55 Cancri e is consistent with supercritical-fluid waterworld theory. As said researchers the planet is likely a rocky world covered with water in a supercritical fluid state and topped off with a steam blanket.