LTT9779 b shouldn’t exist, but here it is, tearing through the universe in a giant metal suit.
Back in 2020, NASA’s TESS mission discovered the exoplanet registered as LT9779 b (planet outside the solar system), which orbits the star LT9779 about 264 light-years from Earth. The celestial body moves in such a close orbit to its star that it goes around it in just 19 hours, and the temperature on its surface is 5170 degrees Celsius.
Since then, the European Space Agency (ESA) has also taken a look at the unusual LT9779 bt with the help of the CHEOPS space telescope for observing exoplanets, and during the mission the organization made some surprising discoveries.
According to the ESA, the celestial body with a diameter 4.7 times that of Earth, or about the same size as Neptune, is the brightest object in the universe so far known, thanks to the metallic cloud layer covering its atmosphere, which reflects 80% of the incoming light. In comparison, the Earth reflects only 30% of sunlight back into space.
The “mantle”, which consists mostly of silicate (a component of sand and glass), metals and titanium, not only gives the planet a shiny appearance, but also ensures the survival of the atmosphere, which is a very surprising development so close to a giant star.
“This is a planet that shouldn’t exist. We would expect such planets to have their atmosphere blown away by their own star, leaving only bare rock behind.”
– says ESA in its statement Vivien Parmentier, co-author of the Mirror Planet study. Celestial bodies that orbit so close to their star are usually gas giants comparable to Jupiter or rocky worlds closer to Earth, but LT9779 b spectacularly breaks the rules known so far.
The CHEOPS mission examining the rebel planet is only the first in a series of similar programs of the ESA, because in 2026 another satellite, Plato, and then in 2029 Ariel will join the search for planets outside the solar system. The former mission will specifically search for Earth-like, potentially habitable celestial bodies, while the latter will focus on the atmospheres of exoplanets.
2023-07-12 16:45:34
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