This story was provided by Tibi Puiu. Tibi is a science enthusiast and co-founder of ZME Science, a popular science blog which aims to bring science back to the people by translating seemingly complicated concepts into layman terms.
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.
For the first time scientists using data from the Kepler and Spitzer space telescopes have mapped the cloud formations of an exoplanet – a planet outside our solar system. The exoplanet in question, called Kepler-7b, doesn’t look one bit like Earth and more resembles Jupiter.
Astronomers all over the world were heartbroken at the news that Kepler – the space telescope tasked with finding extraterrestrial world and which 150 exoplanets had to be discontinued due to technical issues. The telescope however has gathered massive amounts of observational data during its four year long operation – data which will keep scientists busy for many other years to come.
Kepler-7b is such a planet discovered by Kepler. It’s important to note that all these exoplanets haven’t been discovered through direct optical observations. Instead, scientists characterize how light emitted by distant stars varies. Extremely short fluctuations in brightness hint scientists that that a planet is transiting the plane of observations, and, in short, this is how exoplanets are discovered. By analyzing the light spectrum emitted by a distant star, astronomers can discover all sorts of stuff about an exoplanet, like composition, temperature, size, even mass. In this most recent analysis of Kepler-7b, researchers made the first look at cloud structures on a distant world. Previously, astronomers only made temperature maps of exoplanets.
“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 MIT’s Brice-Olivier Demory, lead author of a paper that describes the work 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.”
The clouds of a distant planet
Kepler’s visible-light observations of Kepler-7b’s moon-like phases led to a rough map of the planet that showed a bright spot on its western hemisphere Kepler observations weren’t enough though, so the researchers employed the Spitzer Space Telescope to decipher whether the bright spot was coming from clouds or heat.
Spitzer’s ability to detect infrared light means it was able to measure Kepler-7b’s temperature, estimating it to be between 1,500 and 1,800 degrees Fahrenheit. This is relatively cool for a planet that orbits so close to its star and, according to astronomers, too cool to be the source of light Kepler observed. Instead, they determined, light from the planet’s star is bouncing off cloud tops located on the west side of the planet.
“Kepler-7b reflects much more light than most giant planets we’ve found, which we attribute to clouds in the upper atmosphere,” explained NASA’s Thomas Barclay. “Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time – it has a remarkably stable climate.”
By refining their technique and scoping other distant world’s atmospheres, the NASA scientists hope to reach high resolution analysis that might one day allow them to tell if a distant planet has a similar atmosphere to Earth or not.
“With Spitzer and Kepler together, we have a multi-wavelength tool for getting a good look at planets that are trillions of miles away,” said Paul Hertz, director of NASA’s Astrophysics Division. “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.”