Observation of a New Exoplanet with Metallic Clouds; A Giant Mirror Shining in Space

Researchers say they have observed a very large planet outside the solar system; a very hot planet slightly larger than Neptune that orbits a star similar to the Sun every 19 hours. According to Reuters, this planet appears to be surrounded by clouds of titanium and silicate, causing it to reflect a significant portion of the light it receives like a mirror. This planet was discovered by NASA in 2020 and was studied using 'CHEOPS', the European Space Agency's orbital telescope. James Jenkins, an astronomer from Diego Portales University and the Center of Excellence in Astrophysics and Related Technologies 'CATA', is one of the authors of this research paper published in a scientific journal. He describes this new planet as 'a giant mirror in space'. About 80% of the incoming light to this planet is reflected back into space, making it the most reflective known object in the universe. Venus, the brightest object in the night sky of Earth, apart from the Moon, is surrounded by toxic sulfuric acid clouds and reflects about 75% of its incoming light, while Earth's ratio is about 30%. This new planet is named 'LTT 9779 b' and its star is located in the Milky Way galaxy, 264 light-years away from Earth in the direction of the Sculptor constellation. A light-year is the distance light travels in one year, approximately 9.5 trillion kilometers. The diameter of this planet is about 4.7 times larger than Earth and it orbits very closely to its star (closer than Mercury, the innermost planet of the solar system, to the Sun, and 60 times closer than Earth's orbit). The surface temperature of this planet, with solar radiation from its star, is about 1800 degrees Celsius, hotter than molten lava. According to researchers, the atmospheric distance of this planet to its star is remarkably close; an atmosphere with water-based clouds, like Earth, which was long ago blown away by solar radiation. However, they believe the clouds of this planet are metallic, composed of titanium and silicate, which make up most of the Earth's crust. James Jenkins states, 'We even think that the clouds can condense into droplets and titanium rain may fall in parts of the atmosphere.' Sergio Hoyer, an astronomer and lead of this study from the Marseille Astrophysics Laboratory in France, says, 'No other planet like this has been discovered to date.' According to Vivien Parmentier, an astronomer and one of the study's authors from the Côte d'Azur Observatory in France, having an atmosphere while this planet orbits very close to its star makes it a planet that should not theoretically exist. He added, 'The highly reflective cloud cover likely helps prevent the planet from overheating and losing its atmosphere.' All previously known planets that orbit their stars in less than one Earth day were classified into two categories. They were either 'hot Jupiters'; gas giants similar to the largest planet in the solar system that are much hotter due to solar radiation, or smaller rocky planets than Earth that lack an atmosphere. Researchers are investigating whether this new planet, classified as a 'hot Neptune', started as a gas giant and lost its atmosphere or formed in its current size. More than five thousand exoplanets have been discovered, many of which have very different characteristics from the eight planets of the solar system. With the emergence of more powerful tools like the James Webb Space Telescope, which became operational last year, and the Extremely Large Telescope being constructed in Chile, more discoveries are anticipated. According to researchers, the diversity of exoplanets is astonishing and remarkable.