Scientists have discovered a football-shaped planet known as WASP1
Credit: NASA, ESA and J. Olmsted (STScI)
Nine hundred light-years from Earth, there is a football-shaped planet so hot that heavy metals simmer through its atmosphere and escape into space.
The planet WASP-121b is about ten times hotter than any other known exoplanet its proximity to its host star, which is hotter than the sun. This closeness also gives the planet its unique shape, as the gravitational forces in its atmosphere extend the entire planet.
WASP121-b falls into a category that astronomers call "hot Jupiter" because it's about the same size as the largest planet in our solar system. The exoplanet is 12% to 24% heavier than Jupiter, but the heat that WASP121-b receives from its sun pumps the planet farther than Jupiter in a radius of about 70%.
As researchers studied the light filtering through the exoplanet atmosphere As the planet passed between its host star and the earth, they saw evidence of iron and magnesium high above the surface of the planet – so high that these heavy molecules escaped the planet's gravity and gravity drift off into space. This makes WASP-121b a class of its own. There are other planets hot enough to boil iron and magnesium on the planet's surface, but once in the atmosphere, gravity and the cooler environment conspire to condense these elements into clouds. This unique discovery reveals a new category of ultrafast exoplanets that have been cooked so thoroughly that your cast-iron pan bubbled, turned to gas, and boiled out of the atmosphere.
"Heavy metals were seen in other hot Jupiter, but only in the lower atmosphere," said lead researcher David Sing of Johns Hopkins University in a statement. "So they do not know if they're going to escape or not, and with WASP-121b we see magnesium and iron gas so far from the planet that they are not bound by gravity." [15 Amazing Images of Stars]
The researchers already knew that WASP-121b is one of the most extreme exoplanets ever discovered. On two separate occasions, they launched the Hubble Space Telescope on the planet as he drove past his star to see how ultraviolet (UV) light interacted with the planet's atmosphere.
The researchers not only found unique signatures for the heavy metal release, but also a better understanding of why the upper atmosphere of the planet is so damn hot.  The upper atmospheres of other planets allow much UV radiation. The heavy metals in the outer reaches of the WASP-121b absorb these UV rays and convert this energy into heat. So while the Earth orbits the host star of WASP-121b at such a close range, it may see the most extreme effects on a burnt surface (though the upper atmosphere is likely to be shed), so the upper atmosphere of WASP-121b is vast and fair continue cooking.
Originally published on Live Science .