An international team of researchers has discovered an exoplanet whose atmosphere has no clouds, which represents a breakthrough in the attempt to better understand the planets that are beyond the Solar System.
It is the exoplanet WASP-96b, a gas giant with a temperature of 1,880 degrees Fahrenheit, similar to Saturn in mass, 20 percent larger than Jupiter and which periodically travels a star similar to the Sun to 980 light years.
The lack of clouds in its atmosphere was discovered by a team led by Professor Nikolay Nikolov, of the British University of Exeter, according to a study published today by Nature.
To make the discovery, the team used the Very Large Telecope (VLT) in Chile, with which it studied the atmosphere of the exoplanet as it passed in front of its star. Just as an individual’s fingerprints are unique, so are atoms and molecules, which have a unique spectral characteristic that can be used to detect their presence in celestial objects, says a statement from the University of Exeter. Thus, the spectrum of the exoplanet WASP-96b shows “a complete fingerprint of sodium”, which can only be observed in a cloudless atmosphere, say those responsible for this research.
For a long time, the scientific community has predicted the existence of sodium in the atmospheres of this type of hot giant exoplanets: we have been observing more than 20 exoplanet transit spectra and WASP-96b is the only one that seems to be completely cloud-free and with a clear sodium signal, Nikolov said.
The observations allowed the team of scientists to measure the abundance of sodium in the exoplanet’s atmosphere and conclude that the levels of this element are similar to those found in our own Solar System.
Sodium is the seventh most common element in the Universe and on Earth, in animal life, regulates cardiac activity and metabolism.
Ernst de Mooij, of the City University of Dublin and co-author of this work, stressed that future observations of this cloudless exoplanet will provide “a unique opportunity” to determine the abundance of other molecules, such as water, carbon monoxide and carbon dioxide.