The largest mirror in the universe has been discovered: it is round and measures 60,000 kilometers

Like when we see a very distant lamp around which a nocturnal moth revolves, altering its brightness in a barely perceptible way. “You have to imagine a burning world, very close to its star, with heavy clouds of metal floating overhead, and even dropping titanium droplets on the planet,” he said. James Jenkins, astronomer at Diego Portales University in Santiago de Chileco-author of the study that lasted several months. The mechanism by which these clouds are formed initially aroused perplexity because the planet reaches temperatures of 2000 degrees and therefore the temperature of the atmosphere of this planet is too high not only for clouds of water, but also for metal or glass clouds.

The condensation

He explains it well, and in a very simple way, Vivien Parmentier, co-author of the research and researcher at the Côte d’Azur Observatory. “We realized that we should think of this cloud formation in the same way as the condensation that forms in a bathroom after a hot shower: to heat the bathroom with steam, you can cool the air until the water vapor condenses or you can keep the hot water running until clouds form because the air is so saturated with steam that it simply can’t hold any more.” In short, in even simpler words, clouds of metals form in the atmosphere of LTT9779b despite being very hot because the atmosphere is saturated with silicates and metal vapors, just as clouds form in our bathroom and droplets fall back if we forget to open the water hot, very hot indeed.

Being incredibly bright isn’t the only surprising thing about LTT9779b, no other planet of this size and mass has been found orbiting so close to its star and one comes to think that, if it hadn’t developed this kind of heat shield, the star mother would have already made it evaporate due to too much heat.

The first exoplanet

The first extrasolar planet, 51 Pegasi b, was discovered by Nobel laureates Michel Mayor and Didier Queloz, in 1995, at the Geneva Observatory, with relatively modest instruments, compared to those of the so-called Big Science, but with such a simple research idea how innovative. One of humanity’s great dreams then came true, to know that there are “infinite worlds” beyond our solar system, to quote Giordano Bruno. Today, apart from peculiar cases like these, we are in a very important research for science but almost routine: to date there are 5463 exoplanets around nearby stars, distributed in 4205 solar systems, some very similar to ours, and in any case there are 9719 candidates awaiting confirmation.

If they seem like a lot we think that the smallest ones, like our Earth, we can hardly see them, and in any case we have just left the periphery, we estimate 13 billion light years at least for the universe we see and here we are talking about a few hundred light years, but in our Galaxy alone, the Milky Way, it is estimated that there are several hundred billion planets of all kinds. The search for another Earth has just begun and will take us far. In 2026 we will potentially see some good ones. In fact, Cheops will be joined by the Plato telescope, of a completely different kind but still designed by the same Italian scientists, which will focus on planets similar to the Earth.