NASA's Spitzer Telescope Maps Temperatures of Super-Earth

[LongTomH]

Last edited Fri Apr 1, 2016, 02:46 PM - Edit history (1)

NASA's Spitzer Maps Climate Patterns on a Super-Earth:

Observations from NASA's Spitzer Space Telescope have led to the first temperature map of a super-Earth planet -- a rocky planet nearly two times as big as ours. The map reveals extreme temperature swings from one side of the planet to the other, and hints that a possible reason for this is the presence of lava flows.

"Our view of this planet keeps evolving," said Brice Olivier Demory of the University of Cambridge, England, lead author of a new report appearing in the March 30 issue of the journal Nature. "The latest findings tell us the planet has hot nights and significantly hotter days. This indicates the planet inefficiently transports heat around the planet. We propose this could be explained by an atmosphere that would exist only on the day side of the planet, or by lava flows at the planet surface."

The toasty super-Earth 55 Cancri e is relatively close to Earth at 40 light-years away. It orbits very close to its star, whipping around it every 18 hours. Because of the planet's proximity to the star, it is tidally locked by gravity just as our moon is to Earth. That means one side of 55 Cancri, referred to as the day side, is always cooking under the intense heat of its star, while the night side remains in the dark and is much cooler.

"Spitzer observed the phases of 55 Cancri e, similar to the phases of the moon as seen from the Earth. We were able to observe the first, last quarters, new and full phases of this small exoplanet," said Demory. "In return, these observations helped us build a map of the planet. This map informs us which regions are hot on the planet."

There's a lot more info about this fascinating exoplanet at the JPL news release or at the Spitzer website.

Science has only been able to confirm the existence of planets around other stars since 1988. The first exoplanets were detected by measuring the effect of the planet's gravity on its star; since then, techniques for detecting and studying these mysterious worlds has evolved. NASA lists 1,963 exoplanets on it's Exoplanet Archive page.

Edited to Add: Phil Plait, of Bad Astronomy fame, has more information on 55 Cancri on his blog: Astronomers Map a Distant Super-Earth; But It's a Molten Hell. Phil is great at explaining wonky stuff in layman's language, including 55 Cancri's Phases:

The planet orbits the star so closely that from Earth, we see it pass physically in front of the star once per orbit (called a transit) where it blocks a fraction of the star’s light, and then passes behind the star half an orbit later so the star blocks the planet. Over the course of an orbit the planet undergoes a complete set of phases as seen from Earth, like the phases of the Moon. When it’s in front of the star it’s “new,” and we see its unlit backside. As it circles around it’s a crescent, then half full, then gibbous, then full … but when it’s exactly full, it’s behind the star. Then it pops out again, and we see the phases in reverse.

We don’t see the phases, actually. The planet is too far away from us and too close to the star. But as it undergoes these phases, the amount of light we see from the planet changes. Incredibly, using Spitzer Space Telescope (and some pretty fancy data processing techniques), a team of astronomers was able to measure this teeny change in the light from the planet.