The comet discovered at the same time by two automatic stargazers and named after both is extremely bright. It will return to Earth's proximity only in 80 thousand years
Comet C/2023 A3 (Tsuchinshan-ATLAS) is a rare visitor originating in the Oort Cloud, a distant region of icy bodies beyond Pluto and the Kuiper Belt. The comet was discovered in early 2023, providing a spectacular view as it passes through our inner solar system. It will remain bright enough to view until early November 2024, with the best time to view it before October 24, when it will shine most impressively in the night sky.
These days, given their very long orbits, these two celestial visitors seem to originate in the Oort Cloud, a giant spherical shell of icy bodies located at the far reaches of our solar system. Comet C/2023 A3 Tsuchinshan-ATLAS was discovered in 2023, and identified by observations at the Tsuchinshan Observatory in China—or "Purple Mountain"—and the ATLAS (Last Alert System for Asteroid Encounters) telescope in South Africa. It is officially named in honor of the two observers.
As a comet approaches the Sun, it heats up. The heat causes the ice in it to evaporate and turn into gas, and these gases and dust form the luminous floor and tail, which can stretch for millions of kilometers. The dust tail of Comet Tsuchinshan-ATLAS is prominent in this image, stretching toward the top of the image. A second type of tail, the dovetail, is dimly visible, pointing down and to the right, notes astronomer Bill Cook, who heads the Meteorite Environment Office at NASA's Marshall Space Center.
The sun affects both types of tails in different ways, and sometimes sends them in different directions. The heat and pressure of sunlight pushes the dust tail particles away from the sun, although the tail may bend slightly in the direction the comet came from. In the same way, the solar wind causes the ions to detach from the comet's surface and create the ion tail, which can stretch at a different angle.
Some comets do not survive close encounters with the Sun. If they get too close, the radiation and gravitational forces may break them apart completely. Comet Tsuchinshan-ATLAS did not suffer this fate, but another comet observed by astronomers, C/2024 S1 ATLAS, may have disintegrated. Recent data suggest that this comet, which was expected to be visible from Earth next year, may have recently broken into pieces, Cook said.
