- Gasoline large exoplanet HD 189733 b smells like rotten eggs, astronomers say. The pungent odor is as a result of gasoline hydrogen sulfide on this world’s environment.
- The quantity of hydrogen sulfide is just like that within the environment of Jupiter.
- The invention gives clues as to how gas giant planets kind and evolve.
When finding out distant exoplanets – or worlds orbiting different stars – astronomers look at what they seem like, how massive and large they’re, what sort of environment they’ve and extra. However what about how they scent? We now know that at one exoplanet, not less than, actually stinks … not less than in response to our human sense of scent. On July 8, 2024, astronomers at Johns Hopkins College in Baltimore, Maryland, said that the Jupiter-sized exoplanet HD 189733 b smells like rotten eggs, due to hydrogen sulfide in its environment. They used NASA’s James Webb Space Telescope to make the observations.
The researchers published their peer-reviewed findings in Nature on July 8, 2024.
Meet large exoplanet HD 189733 b
Found in 2005, HD 189733 b is a gas giant exoplanet about the identical dimension as Jupiter. Solely 64 light-years from Earth, it’s the closest recognized hot Jupiter-type exoplanet that transits in entrance of its star as seen from Earth. This makes it splendid for atmospheric examine by astronomers. Sizzling Jupiters are gasoline giants that orbit very near their stars, not like Jupiter and Saturn in our solar system.
The planet orbits 13 instances nearer to its star than Mercury does to our personal sun. It orbits its star in solely two days.
The pungent exoplanet’s environment accommodates carbon dioxide, carbon monoxide, oxygen and water. Since it’s so near its star, it’s scorching scorching, with lethal climate. Temperatures attain 1,700 levels Fahrenheit (930 C) and winds howl at 5,000 mph (8,000 kph). On this world, it doesn’t rain water, it rains tiny particles of glass. The intense winds blow the glass sideways because it falls.
However there’s one thing else on HD 189733 b, which the truth is makes up most of its environment: hydrogen sulfide. That is why the planet smells so dangerous.
Smelly exoplanet smells like rotten eggs
Hydrogen sulfide is thought for being a smelly gasoline. On Earth, it’s one in all many gases launched by volcanic eruptions. Scientists didn’t know that they’d discover it on HD 189733 b, despite the fact that they predicted it must be there. Guangwei Fu, an astrophysicist at Johns Hopkins, was the lead creator of the brand new examine. He stated:
Hydrogen sulfide is a serious molecule that we didn’t know was there. We predicted it will be, and we all know it’s in Jupiter, however we hadn’t actually detected it outdoors the solar system. We’re not searching for life on this planet as a result of it’s means too scorching, however discovering hydrogen sulfide is a stepping stone for locating this molecule on different planets and gaining extra understanding of how several types of planets kind.
Clues to planetary formation
Hydrogen sulfide is a central a part of the sulfur cycle, the biogeochemical cycle of sulfur on Earth. The hydrogen sulfide discovery will assist scientists be taught extra about how planets kind. Sulfur is an important a part of that course of, as Fu defined:
Sulfur is a crucial factor for constructing extra advanced molecules, and – like carbon, nitrogen, oxygen and phosphate – scientists want to review it extra to completely perceive how planets are made and what they’re product of.
Webb will assist scientists detect and examine endure and hydrogen sulfide in different gas giant exoplanets, too. Fu stated:
Say we examine one other 100 scorching Jupiters and so they’re all sulfur enhanced. What does that imply about how they have been born and the way they kind in a different way in comparison with our personal Jupiter?
No methane
Whereas Webb confirmed hydrogen sulfide on HD 189733 b, it additionally established a scarcity of methane. Astronomers had suspected that the planet doubtless wouldn’t have a lot, if any, methane, as a consequence of its scorching temperatures. Fu stated:
We had been pondering this planet was too scorching to have excessive concentrations of methane, and now we all know that it doesn’t.
Heavy metals just like Jupiter
Webb additionally discovered heavy metals in related quantities to these on Jupiter. Typically, heavy metals are typically outlined as metallic components with comparatively excessive densities, atomic weights or atomic numbers. Fu stated:
This Jupiter-mass planet could be very near Earth and has been very properly studied. Now now we have this new measurement to indicate that certainly the steel concentrations it has present an important anchor level to this examine of how a planet’s composition varies with its mass and radius.
The discovering is attention-grabbing, since, in our solar system, the ice giants Uranus and Neptune include extra heavy metals than the gasoline giants Jupiter and Saturn. Scientists say which means Uranus and Neptune gathered extra ice, rock and different heavy components relative to gases like hydrogen and helium after they have been first forming. For the reason that quantity of heavy metals on HD 189733 b is just like Jupiter, that is according to what we all know to date about how planets kind. Fu added:
The findings help our understanding of how planets kind via creating extra stable materials after preliminary core formation after which are naturally enhanced with heavy metals.
The researchers now plan to review extra exoplanets and see how they examine to the pungent exoplanet HD 189773 b.
Backside line: Astronomers say that the large pungent exoplanet HD 189733 b smells so dangerous – like rotten eggs – due to hydrogen sulfide in its environment.
Source: Hydrogen sulfide and metal-enriched atmosphere for a Jupiter-mass exoplanet
Read more: Gas-giant exoplanets cling close to their parent stars
Read more: 1st direct image of 2 giant exoplanets orbiting a sunlike star
