Researchers have created the first cloud map of a planet outside of our solar system.
Astronomers used data from NASA's Kepler and Spitzer space telescopes to analyze the Jupiter-like planet called Kepler-7b. The planet is characterized by an atmosphere of high clouds in the west, and clear skies in the east, a NASA's Jet Propulsion Laboratory (JPL) press release reported.
"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," Brice-Olivier Demory of Massachusetts Institute of Technology in Cambridge, said. "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-7b was one of the first exoplanets (bodies outside of our solar system) discovered by the powerful Kepler telescope, which has now found over 150 planets. The telescope has to retire from its planet-hunting mission after its wheels failed.
Light observations from Kepler-7b's "moon-like phases" allowed researchers to make a rough map that pointed out a bright spot in the planet's western hemisphere. What the team was not able to figure out using Kepler's data was if the spot was cause by clouds or heat. The Spitzer telescope allowed them to answer this question.
Spitzer can detect infrared light, which allowed it to measure the temperature of the mysterious planet. The telescope determined Kepler-7b was between 1,500 and 1,800 degrees Fahrenheit, which is surprisingly cool for a planet that orbits so close to its parent star.
The finding suggests the planet is too cool to produce its own light, so the visible glow must be from light bouncing off atmospheric clouds.
"Kepler-7b reflects much more light than most giant planets we've found, which we attribute to clouds in the upper atmosphere," Thomas Barclay, Kepler scientist at NASA's Ames Research Center, said. "Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time -- it has a remarkably stable climate."
The accomplishment is a step in the right direction for mapping out the atmosphere of other Earth-like planets.
"With Spitzer and Kepler together, we have a multi-wavelength tool for getting a good look at planets that are trillions of miles away," Paul Hertz, director of NASA's Astrophysics Division, said."We're at a point now in exoplanet science where we are moving beyond just detecting exoplanets, and into the exciting science of understanding them."
