NASA Reveals 'Heavy Metal' Planet Shaped Like a Football With 4,600 Degree Atmosphere

Astronomers have revealed fascinating details of a "heavy metal" planet shaped like a football with an upper atmosphere that reaches a scorching 4,600 F, located around 900 light-years from Earth.

According to observations conducted by the Hubble Space Telescope, heavy metals such as iron and magnesium are escaping the planet's upper atmosphere as gases—the first time this phenomenon has been detected in an exoplanet.

The fact that these heavy metals can escape as gases can be explained by the incredibly high temperature of the atmosphere—a result of the planet, dubbed WASP-121b, being so close to its host star.

In fact, WASP-121b's upper atmosphere is around 10 times hotter than that of any other known planet, scientists say.

This proximity to its star also has another intriguing effect on the planet. The star's powerful gravitational forces have warped WASP-121b into an "oblique football shape," according to a study published in the Astronomical Journal.

The planet belongs to a class known as "hot Jupiters"—gas giant exoplanets that orbit extremely close to their host star.

"It is a rare example of a very hot Jupiter, but is particularly unusual in that it is just on the verge of tidal disruption—so it is distorted—and also have a very rich atmosphere we can study," David Sing, lead author of the study from Johns Hopkins University, told Newsweek.

According to Sing, heavy metals have been seen in other hot Jupiters before, but only in the lower atmosphere, so it's not possible to tell whether they are escaping or not.

"With WASP-121b, we see magnesium and iron gas so far away from the planet that they're not gravitationally bound," Sing said in a statement. "We picked this planet because it is so extreme. We thought we had a chance of seeing heavier elements escaping. It's so hot and so favorable to observe, it's the best shot at finding the presence of heavy metals.

"We were mainly looking for magnesium, but there have been hints of iron in the atmospheres of other exoplanets. It was a surprise, though, to see it so clearly in the data and at such great altitudes so far away from the planet. The heavy metals are escaping partly because the planet is so big and puffy that its gravity is relatively weak. This is a planet being actively stripped of its atmosphere."

The latest findings come after astronomers conducted observations of the planet using Hubble's Spectrograph, which detects ultraviolet light. This instrument can help to identify the presence of magnesium and iron gases escaping the upper atmosphere.

According to the researchers, the results of the study will cast new light on our understanding of planetary formation.

"Extreme planets like WASP-121b make ideal laboratories for figuring out how planets work," Sing told Newsweek. "In this case, by studying a hot planet so close to its star, we can investigate how a planet loses its atmosphere."

"In this case we've learned that an exoplanet can not only lose its bulk hydrogen and helium gas, but that this outflowing gas can drag much heavier elements and even metals with it," he said. "This has important consequences in particular for smaller planets such as hot Super Earths, which could have lost most of their primordial hydrogen atmospheres."

This article was updated to include additional comments from David Sing.

This artist's illustration shows an alien world that is losing magnesium and iron gas from its atmosphere. NASA, ESA, and J. Olmsted