A distant planet with clouds loaded with metals looks like “a giant mirror in space”

Investigators said Monday they sighted a planet beyond the scorchingly hot solar system, slightly larger than Neptunewhich orbits a sun-like star every 19 hours and appears to be shrouded in clouds filled with titanium and silicates that reflect most of the light at space.

This is a planet that astronomers say probably shouldn’t even exist.

“It’s a giant mirror in space,” says astronomer James Jenkins, from the Diego Portales University in Chile and the Center of Excellence in Astrophysics and Associated Technologies (CATA) of Chile, co-author of the research published in the journal Astronomy & Astrophysics.

The planet reflects about 80% of incoming light, making it the most reflective known object in the universe. The brightest object in Earth’s night sky other than the Moon, Venus is the most reflective body in our solar system, and is shrouded in toxic clouds of sulfuric acid.

Venus reflects about 75% of the incident light, while Earth reflects about 30%.

The planet, called LTT9779b, and its star are in the Milky Way, about 264 light-years from Earth, in the direction of the constellation of the Sculptor. A light year is the distance that light travels in one year, 9.5 trillion kilometers.

The planet’s diameter is about 4.7 times that of Earth and it orbits very close to its star: closer than Mercury and 60 times closer than Earth’s orbit.

With the scorching solar radiation from its star, its surface temperature is about 1,800 degrees Celsius, hotter than molten lava. The researchers studied the planet using the European Space Agency’s CHEOPS orbiting telescope.

Experts believe that its clouds are made of metals, a combination of titanium and silicate, the material that makes up most of the rocks in the Earth’s crust. “We even believe that the clouds could condense into droplets and cause titanium showers in some parts of the atmosphere”Jenkins explained.

“No other planet like this has been discovered to date”said astronomer and lead author of the study Sergio Hoyer, from the Laboratory of Astrophysics in Marseille, France.

The fact that it has an atmosphere and orbits so close to its star makes it “a planet that shouldn’t exist” according to the astronomer and co-author of the study Vivien Parmentier, from the Côte d’Azur Observatory (France).

“The super-reflective cloud cover likely prevented the planet from getting too hot and losing its atmosphere,” Parmentier explained. “This is quite unique, as all other planets at this temperature that are large enough to support their atmosphere are too hot to form clouds and are therefore as dark as coal.”

The researchers wonder if LTT9779b, also called the “Neptune ultrahot”started out as a gas giant losing most of its atmosphere, or if it started out at its current size.

More than 5,000 planets have been discovered outside our solar system, called exoplanets, many of them with characteristics very different from those of the eight planets inside the system. “The diversity of exoplanets is amazing”Parmentier said“and we have barely scratched the surface.”

Source: Reuters