Astronomy Picture of the Day

Explanation: Comet Tsuchinshan-Atlas is now headed back to the outer Solar System. The massive dusty snowball put on quite a show during its trip near the Sun, resulting in many impressive pictures from planet Earth during October. The featured image was taken in mid-October and shows a defining visual feature of the comet -- its impressive anti-tail. The image captures Comet C/2023 A3 (Tsuchinshan–ATLAS) with impressively long dust and ion tails pointing up and away from the Sun, while the strong anti-tail -- composed of more massive dust particles -- trails the comet and points down and (nearly) toward the recently-set Sun. In the foreground is village of Tai di Cadore, Italy, with the tremendous Dolomite Mountains in the background. Another comet, C/2024 S1 (ATLAS), once a candidate to rival Comet Tsuchinshan-Atlas in brightness, broke up last week during its close approach to our Sun.