Earth's Journal

Space Journal Entry

Space Telescope Spots Super Earth (May 21, 2012)


Artist's impression of "super-Earth" in orbit near its parent star. NASA/JPL-Caltech.

For the first time, NASA's Spitzer Space Telescope detected infrared light from a "super Earth" exoplanet, a planet beyond the solar system. A "super Earth" is one that's more massive than Earth but lighter than giants like Neptune. The exoplanet called 55 Cancri-e is eight times as massive as Earth with twice the diameter. It orbits its parent star in a speedy 18 hours. Because it's so close to the star, surface temperatures are a scorching 3,140°F (2,000°K).

Astronomers theorize 55 Cancri-e has a rocky core that may be surrounded by a blanket of steam from water that quickly boils away. Although it's not within the habitable zone (solar system region neither too hot nor too cold for liquid water), the discovery gives astronomers hope they're getting closer in the search for planets where life might be found. Last year, NASA confirmed discovery of the first "Goldilocks" planet.

The 55 Cancri system is "only" 41 light-years from Earth. A light year is how far light travels in one year, or about 6 trillion miles (10 trillion kilometers). The system includes five planets, with 55 Cancri-e the closest to the star. The same side always faces the star. Its atmosphere is most likely too thin to transfer much heat from the lit to the unlit side.