Skip to main content

Wild exoplanet has metal clouds and rain of liquid gems

In the pantheon of weird exoplanets, one of the strangest has to be WASP-121 b. It’s so close to its star that not only is its surface temperature estimated to be up to an unimaginable 4,600 degrees Fahrenheit, but gravitational forces are pulling the planet apart and shaping it like a football. Now, new research reveals what the weather might be like on this hellish planet, and it’s just as weird as you might think.

Located 855 light-years away, the planet is a type called a hot Jupiter because it’s comparable in mass to Jupiter, at 1.2 times its mass, but its diameter is nearly twice as large. One reason that the planet has such extreme conditions is that it’s close to its star that it is tidally locked, meaning one side of the planet called the dayside always faces the star and has the hottest temperature, while the cooler side called the nightside always faces away from the star into space.

Artist's impression of the exoplanet WASP-121 b.
Artist’s impression of the exoplanet WASP-121 b. It belongs to the class of hot Jupiters. Due to its proximity to the central star, the planet’s rotation is tidally locked to its orbit around it. As a result, one of WASP-121 b’s hemispheres always faces the star, heating it to temperatures of up to 3000 degrees Celsius. The night side is always oriented towards cold space, which is why it is 1500 degrees Celsius cooler there. Patricia Klein and MPIA

In this new study, researchers from the Max Planck Institute for Astronomy looked at the water cycle between the planet’s dayside and nightside. It’s always too hot there for water to form clouds, but that doesn’t mean there aren’t cloudy skies there. The researchers found the nightside has some wild weather phenomena including metal clouds. The clouds consist of metals like iron, magnesium, chromium, and vanadium, which melt into their gas form on the dayside and condense into liquid clouds on the nightside.

And it gets weirder still. The researchers didn’t find indications of aluminum or titanium in the atmosphere, which they expected. They think these metals must have condensed and fallen as rain in lower levels of the atmosphere which they couldn’t see.

“This rain would be unlike any known in the Solar System,” the Max Planck Institute for Astronomy writes. “For instance, aluminum condenses with oxygen to form the compound corundum. With impurities of chromium, iron, titanium, or vanadium, we know it as ruby or sapphire. Liquid gems could therefore be raining on the nightside hemisphere of WASP-121 b.”

Researchers want to study this planet in more detail to learn about its strange ways, and they plan to observe it further using the recently launched James Webb Space Telescope.

“It’s exciting to study planets like WASP-121 b that are very different to those in our Solar System because they allow us to see how atmospheres behave under extreme conditions,” co-author Joanna Barstow said in a statement.

The research is published in the journal Nature Astronomy.

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Astronomers discover extremely hot exoplanet with ‘lava hemisphere’
Like Kepler-10 b, illustrated above, the exoplanet HD 63433 d is a small, rocky planet in a tight orbit of its star. HD 63433 d is the smallest confirmed exoplanet younger than 500 million years old. It's also the closest discovered Earth-sized planet this young, at about 400 million years old.

Astronomers have discovered an Earth-sized exoplanet with an unusually extreme climate where one half of the planet is thought to be covered in lava. The planet HD 63433 d is tidally locked, meaning one side of it always faces its star while the other half always faces out into space, creating a huge difference in temperatures between the planet's two faces.

Like Kepler-10 b, illustrated above, the exoplanet HD 63433 d is a small, rocky planet in a tight orbit of its star. HD 63433 d is the smallest confirmed exoplanet younger than 500 million years old.  NASA/Ames/JPL-Caltech/T. Pyle

Read more
See the weather patterns on a wild, super hot exoplanet
This is an artist’s impression of the exoplanet WASP 121-b, also known as Tylos. The exoplanet’s appearance is based on Hubble data of the object. Using Hubble observations, another team of scientists had previously reported the detection of heavy metals such as magnesium and iron escaping from the upper atmosphere of the ultra-hot Jupiter exoplanet, marking it as the first of such detection. The exoplanet is orbiting dangerously close to its host star, roughly 2.6% of the distance between Earth and the Sun, placing it on the verge of being ripped apart by its host star's tidal forces. The powerful gravitational forces have altered the planet's shape.

When it comes to understanding exoplanets, or planets outside our solar system, the big challenge is in not only finding these planets, but also understanding what they are like. And one of the biggest factors that scientists are interested in is whether an exoplanet has an atmosphere and, if so, what it is composed of. But, just like with weather here on Earth, exoplanet atmospheres aren't static. So the Hubble Space Telescope was recently used for an intriguing observation -- comparing data from an exoplanet atmosphere that had previously been observed, to see how it changed over time.

Hubble looked at planet WASP-121 b, an extreme planet that is so close to its star that a year there lasts just 30 hours. Its surface temperatures are over 3,000 Kelvins, or 5,000 degrees Fahrenheit, which researchers predict would lead to some wild weather phenomena. As it is such an extreme planet, WASP-121 b is well-known and has been observed by Hubble several times over the years, beginning in 2016.

Read more
How astronomers used James Webb to detect methane in the atmosphere of an exoplanet
An artists rendering of a blue and white exoplanet known as WASP-80 b, set on a star-studded black background. Alternating horizontal layers of cloudy white, grey and blue cover the planets surface. To the right of the planet, a rendering of the chemical methane is depicted with four hydrogen atoms bonded to a central carbon atom, representing methane within the exoplanet's atmosphere. An artist’s rendering of the warm exoplanet WASP-80 b whose color may appear bluish to human eyes due to the lack of high-altitude clouds and the presence of atmospheric methane identified by NASA’s James Webb Space Telescope, similar to the planets Uranus and Neptune in our own solar system.

One of the amazing abilities of the James Webb Space Telescope is not just detecting the presence of far-off planets, but also being able to peer into their atmospheres to see what they are composed of. With previous telescopes, this was extremely difficult to do because they lacked the powerful instruments needed for this kind of analysis, but scientists using Webb recently announced they had made a rare detection of methane in an exoplanet atmosphere.

Scientists studied the planet WASP-80 b using Webb's NIRCam instrument, which is best known as a camera but also has a slitless spectroscopy mode which allows it to split incoming light into different wavelengths. By looking at which wavelengths are missing because they have been absorbed by the target, researchers can tell what an object -- in this case, a planetary atmosphere -- is composed of.

Read more