Skip to main content

Heaviest element ever discovered in exoplanet atmospheres is a puzzle

When it comes to finding habitable exoplanets, the next big challenge is not just spotting exoplanets or looking at their orbits, but getting a better understanding of what conditions there might be like by analyzing their atmospheres. New tools like the James Webb Space Telescope will allow us to peer into the atmospheres of exoplanets and see what they are composed of, which can affect the planet’s surface temperature, pressure, and weather systems.

Now, astronomers using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), a ground-based telescope located in Chile, have discovered the heaviest element ever in an exoplanet atmosphere. Looking at two ultra-hot gas giants called WASP-76 b and WASP-121 b, the researchers identified the element barium in their atmospheres.

Artist’s impression of an ultra-hot exoplanet as it is about to transit in front of its host star.
This artist’s impression shows an ultra-hot exoplanet, a planet beyond our Solar System, as it is about to transit in front of its host star. Using the ESPRESSO instrument of ESO’s Very Large Telescope, astronomers have found the heaviest element yet in an exoplanet’s atmosphere, barium, in the two ultra-hot Jupiters WASP-76 b and WASP-121 b. ESO/M. Kornmesser

These two planets orbit extremely close to their respective stars and thus have extremely high surface temperatures which can go over 1,000 degrees Celsius. On one of the planets, WASP-76 b, it gets so got that iron falls from the sky as rain. But the researchers were surprised to find barium high in the atmospheres of these planets because it is so heavy.

Recommended Videos

“The puzzling and counterintuitive part is: why is there such a heavy element in the upper layers of the atmosphere of these planets?” said lead author Tomás Azevedo Silva of the Instituto de Astrofísica e Ciências do Espaço (IA) in Portugal, in a statement.

“Given the high gravity of the planets, we would expect heavy elements like barium to quickly fall into the lower layers of the atmosphere,” said co-author Olivier Demangeon.

The researchers still aren’t sure what is causing this very heavy element to appear in the exoplanet atmospheres, but the fact it has been identified in not one but two different hot Jupiter atmospheres is interesting. Further research will be needed to discover where this barium came from and how it stays so high in the atmosphere.

The research is published in the journal Astronomy & Astrophysics.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
This distant exoplanet has an atmosphere ‘like something out of science fiction’
Tylos (or WASP-121b) is a gaseous, giant exoplanet located some 900 light-years away in the constellation Puppis. Using the ESPRESSO instrument on ESO’s Very Large Telescope (VLT), scientists have been able to prove into its atmosphere, revealing its 3D structure. This is the first time that this has been possible on a planet outside of the Solar System. The atmosphere of Tylos is divided into three layers, with iron winds at the bottom, followed by a very fast jet stream of sodium, and finally an upper layer of hydrogen winds. This kind of climate has never been seen before on any planet.

For decades, astronomers have been wondering about planets beyond our solar system -- called exoplanets -- and whether we could learn about these far-off worlds. With the introduction of tools like the James Webb Space Telescope, we're now able to not only detect exoplanets, but also to learn about them in detail. Recently, astronomers created the first 3D view of an exoplanet atmosphere, letting them peer into the climate of another world.

The researchers used a ground-based telescope, the European Southern Observatory’s Very Large Telescope (ESO’s VLT), which consists of four telescopes that work together to take detailed readings of distant objects. They found that exoplanet WASP-121b, which has surface temperatures of over 3,000 Kelvins, or 5,000 degrees Fahrenheit, is so hot that metals like iron and titanium can be whipped up into the atmosphere, carried by powerful winds.

Read more
NASA to host first ever Twitch stream from International Space Station
NASA astronaut Don Pettit aboard the International Space Station.

The job of space agencies like NASA isn't only to research scientific topics and to push forward space exploration -- it's also to communicate with the public about that work, and to get them excited for space research. To that end, NASA frequently hosts events like astronauts in space answering questions from school children, collaborating with citizen science projects, or encouraging amateur astronomers and curious stargazers to participate in astronomical events. Now, the agency's latest push to engage young people is to go where many of them are: on Twitch.

NASA will host its first Twitch event from the International Space Station next week, in a move hoping to draw in a new audience interested in space science and research. The event will have NASA astronauts currently living on the space station talk about their life on board and the work that they're doing, and give Twitch viewers the opportunity to ask them questions.

Read more
Wild supersonic winds whip around this extreme exoplanet
This artist’s visualisation of WASP-127b, a giant gas planet located about 520 light-years from Earth, shows its newly discovered supersonic jet winds that move around the planet’s equator. With a speed of 9 km per second (33 000 km/h), this is the fastest jetstream of its kind ever measured in the Universe.

Planets outside our solar system can be wild, weird places. Astronomers have discovered exoplanets shaped like a rugby ball, or where it rains gems, or which have one hemisphere covered in lava. And now there's a new oddity to add to the catalog: a planet with winds that are faster than the speed of sound.

WASP-127b is a huge, puffy sphere which is one of the least dense planets ever discovered. It is larger than Jupiter, but has less than a fifth of Jupiter's mass, making it unlike anything in our solar system. And its oddity has made it a favorite target for study, with astronomers observing clouds there in 2022, making it one of the few detections of clouds on a planet outside our solar system.

Read more