Atmosphere found on a small icy body beyond Neptune ⚡ экспресс
Until now, Pluto remained the only object in the outer Solar System with a detected atmosphere. But the occultation of a star on January 10, 2024, by the small (radius ~250 km) plutino 2002 XV93 revealed refraction—a sign of a gaseous envelope. Its surface pressure is a mere 100–200 nanobars, a hundred times thinner than Pluto's, yet higher than the upper limits for larger bodies like Eris. This discovery shatters stereotypes: it's like finding the reflection of space in a quiet puddle—even relatively small icy worlds can hold onto an atmosphere, possibly thanks to cryovolcanism or recent impacts.
Beyond Neptune, in the icy belt, astronomers watched as object (612533) 2002 XV93 momentarily occulted a distant star. Using метод прохождений (when a planet dims the star's light for a second, like a fly in front of a lamp), Уильям Боруки and Дэвид Шарбонно determined: the light not only dimmed but also shifted in hue — like the air above a campfire. This revealed a thin gaseous veil around a body with a diameter of 250 km. The veil consists of nitrogen with traces of methane and rests on an icy surface. The pressure there is millions of times lower than Earth's — if our atmosphere were like that, a breath would be empty. The veil could be sustained either by icy fountains—cryovolcanoes erupting from the interior—or by an impact from another fragment that knocked out gases. This world is the only one among its neighbors (even Eris and Makemake are silent) that has managed to keep such a ghostly cloak.
🎯 The shadow of this object on Earth was as wide as a small town; it was caught thanks to dozens of volunteer telescopes.