Hubble Space Telescope reveals two strange planets where it rains vapourised rock and the atmosphere is ‘sunburned’

The planets are ‘super-hot Jupiters’, large celestial bodies so close to their sun that they experience scorching temperatures

(NASA, ESA, Leah Hustak (STScI))

New research from the Hubble Space Telescope has revealed details behind two ‘super-hot Jupiter’ planets, one where it rains vapourised rock and another where its atmosphere is being “sunburned” by its star.

‘Hot Jupiters’ are extremely large planets that experience scorching temperatures due to their proximity to their sun. These bodies reach temperatures above 1,600 degrees Celsius, which is hot enough to vaporize most metals, including titanium, and are the hottest planetary atmospheres humans have ever discovered.

"We still don’t have a good understanding of weather in different planetary environments," said David Sing of the Johns Hopkins University in Baltimore, Maryland, co-author on the two studies on the planets.

"When you look at Earth, all our weather predictions are still finely tuned to what we can measure. But when you go to a distant exoplanet, you have limited predictive powers because you haven’t built a general theory about how everything in an atmosphere goes together and responds to extreme conditions. Even though you know the basic chemistry and physics, you don’t know how it’s going to manifest in complex ways."

One of the planets called WASP-178b, located about 1,300 light-years away, has a cloudless atmosphere with one side permentantly facing its star. Its silicon monoxide atmosphere is whipped around, creating hurricanes of over 2,000 miles per hour, while on its dark side the gas cools to form clouds that rain rocks, which vaporise on the planet’s surface.

On the other planet, KELT-20b, a blast of ultraviolet light from its star is creating a thermal layer in its atmosphere – a never-before-seen event, scientists say. "Until now we never knew how the host star affected a planet’s atmosphere directly. There have been lots of theories, but now we have the first observational data," Guangwei Fu of the University of Maryland, College Park, said of the mysterious world 400 light years away.

"The emission spectrum for KELT-20b is quite different from other hot-Jupiters," Fu said. "This is compelling evidence that planets don’t live in isolation but are affected by their host star."

Although these planets are too hot to be inhabited by humans, studying them could give scientists the knowledge that will help us understand the atmospheres of planets that could support human life. The observational data from super-hot Jupiters help train scientists for information from terrestrial exoplanets.