A Giant Exoplanet the Size of Jupiter Rains Glass, Smells Like Rotten Eggs

Researchers are learning more and more about the wider universe, and a recent discovery tells us a little more about the catchily named exoplanet HD 189733 b. One notable tidbit from the latest research is that this particular planet, dubbed a “hot Jupiter,” stinks like rotten eggs due to an abundance of hydrogen sulfide in the atmosphere. 

The report was published July 8 in the science journal Nature. In the study, researchers used specialized filters on the James Webb Space Telescope to measure the atmosphere of HD 189733 b. In addition to its highly unpleasant stench, researchers also found some water, carbon dioxide and carbon monoxide while simultaneously ruling out the existence of methane.  

While hydrogen sulfide is very unpleasant to the human nose, it is still an important discovery. This marks the first instance of hydrogen sulfide being found on a planet outside our solar system. Hydrogen sulfide contains sulfur, which results in the familiar rotten-egg stink. In short, the planet would be very smelly if you could stand to be on it for even a fraction of a second. 

“Hydrogen sulfide is a major molecule that we didn’t know was there. We predicted it would be, and we know it’s in Jupiter, but we hadn’t really detected it outside the solar system,” said Guangwei Fu, astrophysicist at Johns Hopkins who led the research. “Sulfur is a vital element for building more complex molecules, and—like carbon, nitrogen, oxygen, and phosphate—scientists need to study it more to fully understand how planets are made and what they’re made of.”

Fu also notes that researchers are not looking for life on this planet, because it’s a gas giant and also too hot. The planet is 13 times closer to its star than Mercury is to the sun. The close proximity causes temperatures as low as 1,200 degrees Fahrenheit and upwards of 1,700 degrees Fahrenheit, according to researchers at Caltech. That’s why it’s referred to as a hot Jupiter, because it’s very hot and it’s a gas giant that is about the size of Jupiter. 

Closest exoplanet to Earth

Exoplanets describe planets that exist outside of Earth’s solar system. None of them are particularly close, but HD 189733 b is one of the closest ones at around 64 light years away from Earth, according to NASA. It would take NASA space probe Voyager 1 approximately one million years to get there at its current pace of 38,200 mph. While other exoplanets are closer to Earth, HD 189733 b is the closest hot Jupiter-style planet in our cosmic neighborhood.

Earthlings won’t be colonizing that planet any time soon and it’s not just for distance reasons. On top of its absurdly high temperatures, the planet is also widely known for its 5,400 mph winds that whip the planet’s precipitation around so quickly that it basically rains sideways. It also doesn’t help that the rain is shards of molten glass, making for one of the worst thunderstorms imaginable. 

Despite it basically being hell in planet form, HD 189733 b is an important planet for research. It was one of the first exoplanets to have a thermal map made of it. NASA also used the Hubble Space Telescope to measure the planet’s water vapor levels and found nearly nothing. That, along with this most recent study, tells scientists a lot more about how planets outside of our solar system are and how they’re formed.