Was discovered in 2023

Is a bright comet hurtling towards Earth in the fall?

(Bild: Ariel Graykowski, Samantha Hemmelgarn, Thomas M. Esposito, Franck Marchis, David Koster, Darren Rivett & Masao Shimizu (CC BY 4.0))

A comet may be visible to the naked eye in the night sky this fall. It is a celestial body called Tsuchinshan-ATLAS (C/2023 A3), which could perhaps even become as bright as Venus.

C/2023 A3 was discovered on February 22, 2023 using the Asteroid Terrestrial-impact Last Alert System (ATLAS for short) in South Africa, a robotic early warning system specifically designed to detect near-Earth asteroids a few weeks to a few days before their possible impact on Earth.

Tsuchinshan-ATLAS was originally thought to be an asteroid, but it was later discovered that the same object had been photographed six weeks earlier by the Purple Mountain Observatory (Tsuchinshan) east of Nanjing, China.

What are comets?

Comets are considered to be remnants of the formation of our solar system around 4.6 billion years ago. They consist of a mixture of ice, dust and rock and are therefore often compared to dirty snowballs. The ice contains not only frozen water, but also carbon dioxide ("dry ice"), methane and ammonia, among other things.

Probably comes from the Oort cloud
C/2023 A3 probably originated in the so-called Oort cloud. This is a distant region of space that is thought to be home to trillions of comets.

Astronomers have now discovered that it is indeed an incoming comet. According to calculations, it will approach up to around 58 million kilometers on 27 September. This also corresponds to the average distance of the closest planet to the sun, Mercury.

Visible in the western evening sky
Two weeks later, on 12 October, comet C/2023 A3 will only be around 71 million kilometers away from Earth. According to experts, the figures calculated to date indicate that the celestial body could develop a remarkable tail, which could make for a striking sight in the western evening sky in mid-October.