Scientists have recently found an exoplanet where it rains rocks, and lava fills the oceans, so they’ve fittingly called it a “hell planet.” Winds there reach supersonic speeds, and temperatures can reach over 5,400 degrees Fahrenheit. It gets so hot there that the rocks not only melt but become vaporized, creating a thin, inhospitable atmosphere. Because it orbits so close to its host star, planet K2-141b remains fiery hot at all times.
“Our finding likely means that the atmosphere extends a little beyond the shore of the magma ocean, making it easier to spot with space telescopes,” said co-author Nicolas Cowan.
The bizarre hell planet is located around 210 light-years away from Earth, and its host star is slightly smaller than our Sun. Astronomers have said they have discovered few exoplanets as extreme as this one. Their findings have been published in Monthly Notices of the Royal Astronomical Society. Scientists from McGill University, York University, and the Indian Institute of Science Education contributed to this hellish planet’s research.
The conditions of the lava planet
The lava planet resembles the size of Earth, but the weather patterns and atmosphere differ greatly. The exoplanet’s atmosphere, surface, and oceans all consist of one ingredient: rocks. Winds on the planet can reach over 5000 km/hr, and the lava oceans have a depth of over 100 km. Computer simulations run by the scientists predict continued extreme weather, which could permanently change the lava planet’s atmosphere.
“The study is the first to make predictions about weather conditions on K2-141b that can be detected from hundreds of light-years away with next-generation telescopes such as the James Webb Space Telescope,” lead author Giang Nguyen said in a news release.
Since the planet orbits are so close to its host star, it completes one revolution in only six or seven hours. In comparison, the closest planet to our Sun, Mercury, takes about 87 days to complete one orbit.
When the researchers looked at K2-141b’s illumination pattern, they discovered that the sun never sets on two-thirds of the planet. Because it revolves so closely to its host star, the gravitational pull gives one side of the planet perpetual sunlight. This also explains the scorching hot temperatures on the planet. On the dark side of the planet, temperatures can reach a bone-chilling negative 328 degrees Fahrenheit.
What creates the lava?
Because of the scorching temperatures on the sunny side, the rock’s become vaporized, forming precipitation. Water evaporates, goes into the atmosphere, condenses, and comes back as rain in the water cycle on Earth. On the hell planet, sodium, silicon monoxide, and silicon dioxide form the rocks go through this process as well.
On Earth, the rainwater flows back into the oceans, repeating the water cycle. But on the lava planet, the rock vapor gets blown into the dark side by the supersonic winds. The rocks rain back down into the magma oceans, and the currents flow back to the sunny side. There, the cycle is repeated, and rocks evaporate once more.
However, scientists say the hell planet’s “rock cycle” doesn’t have the same stability as Earth. The magma ocean’s currents move slowly, and due to this, scientists predict a change in the mineral composition over time. This will cause alterations to the surface and atmosphere of the planet.
“All rocky planets, including Earth, started as molten worlds but then rapidly cooled and solidified. Lava planets give us a rare glimpse at this stage of planetary evolution,” says Professor Cowan of the Department of Earth and Planetary Sciences.
The scientists will test these predictions in their next phase of research. The team obtained data from the Spitzer Space Telescope, which should give them an idea of the exoplanet’s day-side and night-side temperatures. The launch of the James Webb Space Telescope in 2021 will greatly help them in verifying their predictions.
Other hellishly hot exoplanets discovered.
Similar exoplanets have been discovered recently, such as WASP-76b located around 640 light-years from Earth. While it may not have lava oceans, it has a strange characteristic: it rains liquid iron. Temperatures here can exceed 4,350 degrees Fahrenheit, which can easily vaporize metals.
Researchers first discovered this planet using the Very Large Telescope (VLT) at the European Southern Observatory (ESO). It also orbits close to its host star, which causes one side to remain in perpetual sunlight. While that side resembles hell, the other side stays constantly dark and cool. Strong winds on this planet blow the vaporized iron into the dark side, which causes the iron to condense into droplets, forming rain.
On the hot side, the planet gets thousands of times more radiation from its host star than the Earth does from the Sun. This intense heat creates strong winds that carry the iron vapor from one side to the other. There, the temperatures cool off to around 1,500 degrees Celsius – still insanely hot.
“One could say that this planet gets rainy in the evening, except it rains iron,” David Ehrenreich, professor at the University of Geneva in Switzerland, said in a press release. Ehrenreich led the study on WASP-76b, which got published in the journal Nature. Located in the constellation Pisces, it’s a gas giant like Jupiter and Saturn in our solar system.
Using the new ESPRESSO instrument on ESO’s VLT in the Chilean Atacama Desert, astronomers observed day-night chemical differences for the first time on a Jupiter-like planet. They discovered a large amount of iron vapor separates the planet into two sides. Astronomers from Portugal, Italy, Switzerland, Spain, and ESO made these observations in September 2018.
The team will keep using the spectrograph to locate other Earth-like planets and exoplanets with extreme atmospheres. “What we have now is a whole new way to trace the climate of the most extreme exoplanets,” said Ehrenreich.