Scientists generate first map of clouds on an exoplanet

[Judi Lynn]

Scientists generate first map of clouds on an exoplanet

Map reveals a lopsided cloud distribution on an extremely hot planet.

Jennifer Chu, MIT News Office
October 3, 2013


[font size=1]
Kepler 7b (left), which is 1.5 times the radius of Jupiter (right), is the
first exoplanet to have its clouds mapped. The cloud map was produced
using data from NASA's Kepler and Spitzer space telescopes.
Image: NASA/JPL-Caltech/MIT[/font]

On the exoplanet Kepler 7b, the weather is highly predictable, an international team of scientists has found: On any given day, the exoplanet, which orbits a star nearly 1,000 light-years from Earth, is heavily overcast on one side, while the other side likely enjoys clear, cloudless weather.

The new work, by researchers from MIT and other institutions, is the first mapping of the distribution of clouds on an exoplanet. The scientists observed that one of Kepler 7b’s hemispheres is blanketed with a dense layer of clouds — far denser than any found on Earth, and so thick that it reflects a significant portion of its host star’s incoming light. This shield of clouds makes the planet cooler than others of its type, creating an atmosphere that encourages further cloud formation.

The team generated a low-resolution map of the planet’s clouds using optical data from NASA’s Kepler Space Telescope. The researchers also analyzed the light originating from Kepler 7b at various phases of its orbit, finding that much of the planet’s reflectivity is due to the presence of clouds, and that this cloud cover is unevenly distributed.

“There are a lot of different chemical processes that could take place to create this inhomogenous cloud,” says Nikole Lewis, a postdoc in the Department of Earth, Atmospheric and Planetary Sciences (EAPS). “Kepler 7b is an important test-bed for the way circulation and cloud distribution work together in exoplanet atmospheres.”

More:
http://web.mit.edu/newsoffice/2013/scientists-generate-first-map-of-clouds-on-kepler-7b-1003.html

[Judi Lynn]

1. Patchy Clouds on an Exotic World

Patchy Clouds on an Exotic World
Source: JPL press release
New Planets
Posted: 10/03/13

Astronomers using data from NASA’s Kepler and Spitzer space telescopes have created the first cloud map of a planet beyond our solar system, a sizzling, Jupiter-like world known as Kepler-7b.

The planet is marked by high clouds in the west and clear skies in the east. Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars, but this is the first look at cloud structures on a distant world.

“By observing this planet with Spitzer and Kepler for more than three years, we were able to produce a very low-resolution ‘map’ of this giant, gaseous planet,” said Brice-Olivier Demory of Massachusetts Institute of Technology in Cambridge. Demory is lead author of a paper accepted for publication in the Astrophysical Journal Letters . “We wouldn’t expect to see oceans or continents on this type of world, but we detected a clear, reflective signature that we interpreted as clouds.”

Kepler has discovered more than 150 exoplanets, which are planets outside our solar system, and Kepler-7b was one of the first. The telescope’s problematic reaction wheels prevent it from hunting planets any more, but astronomers continue to pore over almost four years’ worth of collected data.

More:
http://www.astrobio.net/pressrelease/5720/patchy-clouds-on-an-exotic-world

[Judi Lynn]

2. Planet shrouded in green clouds? NASA cloud mappers seek new Earths

Planet shrouded in green clouds? NASA cloud mappers seek new Earths
By Amina Khan
October 2, 2013, 9:32 a.m.

Scientists have discovered that a huge, gassy exoplanet called Kepler-7b is covered with patchy clouds of silicates that might even rain liquid rock -- even though it’s within scalding distance of its parent star.

The findings, set to be published in Astrophysical Journal Letters, are the first to map cloud structures on a world beyond our solar system and could one day be used to study clouds on smaller, more Earth-like planets.

The planet Kepler-7b, whose star sits in the constellation Lyra, was one of the earliest discoveries using NASA’s now-hobbled Kepler space telescope.

“We consider it a hot Jupiter because it’s very close to its star," Demory said. "We think it’s tidally locked.” This means it can’t rotate freely and always shows the same face to its parent star – just as the moon does toward Earth.

More:
http://www.latimes.com/science/sciencenow/la-sci-sn-planet-kepler-clouds-map-hot-jupiter-exoplanet-silicate-rain-20131001,0,7830207.story