'A Giant Mirror In Space': Metallic Clouds Found On Alien Planet

Astronomers suggest that this planet should not exist based on their findings.

On Monday, researchers announced the discovery of an incredibly unusual exoplanet located outside our solar system.

This scorching planet, slightly larger than Neptune, revolves around a star similar to our sun every 19 hours.

It is enveloped in metallic clouds composed of titanium and silicates, which reflect the majority of incoming light back into space.

"It's a giant mirror in space," said astronomer James Jenkins of Diego Portales University and the Center for Excellence in Astrophysics and Associated Technologies (CATA) in Chile, a co-author of the research published in the journal Astronomy & Astrophysics.

LTT9779b, the planet in question, possesses an exceptional level of reflectivity, with approximately 80% of incoming light bouncing off its surface. This makes it the most reflective object known in the universe.

In comparison, Venus, known for its brightness in Earth's night sky, is the most reflective object in our solar system, reflecting around 75% of incoming light. Earth, in contrast, reflects approximately 30% of incoming light.

Situated in the constellation Sculptor, LTT9779b and its host star reside within the Milky Way galaxy, approximately 264 light years away from Earth.

To put it into perspective, a light year represents the distance light travels in one year, equivalent to about 5.9 trillion miles (9.5 trillion km).

The diameter of the planet LTT9779b is approximately 4.7 times larger than Earth. It has an incredibly close orbit around its star, even closer than Mercury's proximity to the Sun in our solar system and 60 times closer than Earth's orbit.

The planet is subjected to intense solar radiation, resulting in a surface temperature of approximately 3,270 degrees Fahrenheit (1,800 degrees Celsius), surpassing the heat of molten lava.

Considering the planet's close proximity to its star, researchers find it remarkable that it possesses any atmosphere at all.

They speculate that an atmosphere similar to Earth's, characterized by water-based clouds, would have been eradicated by the intense solar radiation over time.

However, they propose that the planet's clouds are metallic in nature, consisting of a combination of titanium and silicate, which are primary components found in the rocks of Earth's crust.

"We even think that the clouds could condense into droplets, and have titanium rain falling in parts of the atmosphere," Jenkins said.

The researchers studied the planet using the European Space Agency's CHEOPS orbiting telescope.

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

Astronomer and co-author of the study, Vivien Parmentier from the Côte d'Azur Observatory in France, describes the presence of an atmosphere on the planet despite its close proximity to the star as a paradoxical characteristic, labeling it "a planet that shouldn't exist."

"The super-reflective cloud cover likely helped stop the planet from warming up too much and being stripped of its atmosphere," Parmentier said. "This is quite unique as all other planets at this temperature that are big enough to keep their atmosphere are too hot to form clouds and are thus as dark as charcoal."

LTT9779b also exhibits characteristics of being tidally locked to its star, similar to how the Moon is tidally locked to Earth. This means that one side of the planet always faces the star, experiencing a perpetual day, while the other side remains in constant darkness.

In the past, planets that orbited their stars in less than one Earth day were predominantly categorized as "hot Jupiters," gas giants similar in composition to Jupiter but significantly hotter due to intense solar radiation.

Alternatively, smaller rocky planets similar in size to Earth, lacking an atmosphere, were also observed in such short orbits.

The researchers are contemplating the origins of LTT9779b, an "ultra-hot Neptune," and whether it may have initially formed as a gas giant but lost a substantial portion of its atmosphere, or if it originated at its current size, Reuters reported.

"The diversity of exoplanets is stunning," Parmentier said, "and we have just scratched the surface."

With the advancements in observational instruments, such as the operational James Webb Space Telescope and the upcoming Extremely Large Telescope in Chile, more exciting discoveries are anticipated in the field of exoplanet research.

Over 5,000 exoplanets have already been identified, each presenting unique characteristics that differ significantly from the eight planets in our own solar system.