Spitzer sees the light of alien ‘super earth’
NASA’s Spitzer Space Telescope was able to detect a super Earth’s direct light for the first time using its sensitive heat-seeking infrared vision. The planet is called 55 Cancri e and it’s a toasty world about twice the size of the Earth that rushes around its star every 18 hours.
It orbits so closely — about 25 times closer than Mercury is to our sun — that it is tidally locked with one face forever blisters under the heat of its sun. The planet has a rocky core surrounded by a layer of water in a supercritical state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam.
Spitzer was able to see the light of the planet by watching it slip behind its star in what is called an occultation. Because the planet is brighter relative to its star when viewed in infrared light, Spitzer was able to measure the slight drop in total brightness that occurred as the planet disappeared from view.
In this current study, the Spitzer data revealed that 55 Cancri e is very dark and that its sun-facing side is blistering hot at 2,000 kelvins or 3,140 degrees Fahrenheit.
Above: 1. Artist’s concept of 55 Cancri e. 2. A graphic showing how astronomers detected the light from 55 Cancri e using the Spitzer Space Telescope.