So, an international team of scientists has discovered for the first time a cloudless exoplanet, WASP-96b. The sodium shines brightly in this world.
Here’s the story. Hot gas giants outside of our solar system are rich in sodium, which is the seventh-most common element in the universe. But the clouds that dominate the exoplanetary atmospheres typically obscure such signatures. Thus, the clarity of this spectrum has convinced astronomers that the new planet’s atmosphere has no clouds at all.
The team, led by Nikolay Nikolov, an astronomer at the University of Exeter in the United Kingdom, detected this hot gas giant, known as WASP-96b, using the European Southern Observatory’s Very Large Telescope in Chile.
So, WASP-96b is the first evidence of an entirely cloudless planet. It is also the first time astronomers find a planet with such a clear sodium signature.
Scientists published the research on May 7 in the journal Nature.
While looking at the spectrum of WASP-96b, astronomers found that the spectral signal for sodium was shaped like a tent (left). This means that the planet is cloud-free, as a cloud deck would partially truncate the spectral signature (right). Credit: N. Nikolov/E. de Mooij
This “hot Saturn” lies nearly 1,000 light-years from Earth. It is about 20 percent larger than Jupiter and has roughly the same mass as Saturn. Also, the exoplanet is extremely hot, at 1,300 kelvins (1,900 degrees Fahrenheit, or 1,000 degrees Celsius)
However, the abundance of sodium on WASP-96b could also hint at planetary conditions. The amount of the sodium on this exoplanet is similar to those found throughout our own solar system and on Earth.
This elusive element regulates metabolism in humans and animals, is an abundant component of our oceans, and makes up about 2.6 percent of our crust.
But astronomers won’t stop here. By studying this exoplanet they might even have a great opportunity to determine the abundances of other molecules, such as water, carbon monoxide, and carbon dioxide.
NASA’s Hubble Space Telescope and the upcoming James Webb Space Telescope will be their greatest instruments to further study WASP-96b.
Thumbnail image: This is an artistic visualization of the exoplanet WASP-96b, which appears blue. Credit: Engine House