The exoplanet known as WASP-18b very much lives up to its informal “death planet” moniker. And while the object is hardly different from the average uninhabitable “hot Jupiter,” NASA scientists have been especially piqued by the exoplanet’s peculiar upper atmosphere, which is almost completely made up of carbon monoxide.
Given the unusual carbon monoxide-dominated stratosphere and the fact that WASP-18b does not have any water at all, the researchers behind the new discovery believe that the exoplanet, while similar in some ways to most other hot Jupiters, might have formed in a completely different manner, the Independent wrote.
“The composition of WASP-18b defies all expectations,” read a statement from lead author Kyle Sheppard of NASA’s Goddard Space Flight Center.
“We don’t know of any other extrasolar planet where carbon monoxide so completely dominates the upper atmosphere.”
As explained by Newsweek, the fact that some sources have dubbed WASP-18b as the “Death Planet” doesn’t change how other hot Jupiters, as well as Jupiter itself, have similarly “brutal” capabilities. Most other planets or exoplanets of this kind have atmospheres that are usually rich in titanium oxide, vanadium oxide, and other related chemicals. Likewise, WASP-18b’s upper atmosphere was also shown to have some chemicals that absorb sunlight.
What made WASP-18b different from other hot Jupiters, however, was the “messy mix” of data regarding the chemicals that are found in its upper atmosphere. Based on models ran by the NASA scientists behind the study published this week in The Astrophysical Journal Letters, WASP-18b had to have an atmosphere exclusively composed of carbon dioxide and carbon monoxide. Ultimately, carbon dioxide was ruled out, as there was no water found on the surface of the “Death Planet” after several attempts to find the substance with NASA’s Hubble Space Telescope.
That left the scientists with an upper atmosphere almost solely made up of carbon monoxide and still able to absorb the sun, but no traces of water anywhere on the exoplanet — a first-of-its-kind situation that the researchers believe “opens a new window” into how we understand the processes that create exoplanetary atmospheres.
Peculiar as WASP-18b may be as the “Death Planet,” scientists are looking forward to learn more about this exoplanet and others of its kind, while leveraging upcoming forms of technology such as the James Webb Space Telescope, which is expected to launch in 2019. According to Goddard exoplanet scientist and study second author Avi Mandell, this telescope and other space-based observatories will be instrumental in follow-up studies on the wide range of exoplanets out there in our universe.