The smelly nearby planet smells like rotten eggs – but experts reveal why the stench is actually a good thing

Approximately 64.5 light-years away, an exoplanet famous for its violent weather has gained fame in another department: its smell.

Its atmosphere stinks of rotten eggs, according to data captured by the James Webb Space Telescope and analyzed by researchers at Johns Hopkins University.

And while that would be hell for you or me, scientists think it might actually be a good thing for understanding how planets are “born.”

The gas giant, dubbed HD 189733 b, has traces of hydrogen sulfide in its atmosphere – making the entire planet smell like sulfur, or rotten eggs.

“Hydrogen sulfide is an important molecule that we didn’t know existed. We predicted it would be, and we know it’s on Jupiter, but we haven’t detected it outside the Solar System,” said Guangwei Fu, an astrophysicist at Johns Hopkins who led the research.

“We are not looking for life on this planet because it is too hot, but finding hydrogen sulfide is a stepping stone to finding this molecule on other planets and gaining a greater understanding of how different types of planets form.”

Along with hydrogen sulfide, Fu’s team discovered that HD 189733 b’s atmosphere is mainly made up of water, carbon dioxide and carbon monoxide.

“Sulfur is a vital element for building more complex molecules and – like carbon, nitrogen, oxygen and phosphate – scientists need to study it further to fully understand how planets are made and what they are made of. ,” Fu added.

The planet is approximately the size of Jupiter, the largest in our solar system, which means that around 1,300 terrestrial planets could fit inside it, according to NASA.

But unlike Jupiter, which is deadly cold, HD 189733 b is closer to its own version of the Sun, earning it the common astronomical nickname “hot Jupiter.”

“Let’s say we study another 100 hot Jupiters and they are all enriched in sulfur,” asked Fu.

“What does this mean about how they were born and how they form differently compared to our own Jupiter?”

Fu’s team was able to rule out the presence of methane with “unprecedented precision” thanks to the $10 billion James Webb Space Telescope.

“We were thinking that this planet was too hot to have high concentrations of methane, and now we know that’s not the case,” he continued.

We want to know how these types of planets got there

Guangwei Fu, astrophysicist at Johns Hopkins

The team also measured levels of heavy metals, commonly found on Jupiter.

Fu believes this will help answer questions about whether a planet’s metallicity correlates with its mass — and how much or how little.

Our solar system’s icy planets, like Neptune, tend to contain more metals than gas giants like Jupiter or Saturn.

But whether this is true for exoplanets – planets that lie outside our solar system – remains a mystery.

“This Jupiter-mass planet is very close to Earth and has been very well studied.

“Now we have this new measurement to show that, in fact, metal concentrations provide a very important anchor point for this study of how a planet’s composition varies with its mass and radius,” Fu said.

“The findings support our understanding of how planets form by creating more solid material after initial core formation and then being naturally enhanced with heavy metals.”

But what Fu’s team is really trying to figure out is this: “We want to know how this type of planet got there,” he said.

And understanding what the atmospheres of different exoplanets are made of will hopefully answer that question.