The green comet - Comet 2022 E3 (ZTF) - will be closest to Earth on February 1 and 2. It's prime time to view this comet, which might be the brightest of 2023.
Asteroid close encounter today! Near-Earth asteroid (2023 BU) will pass safely 2,174 miles (3,500 km) away from Earth. Details here on how to watch online.
Watch for Mercury in the east before sunup in January 2023. Mercury reaches greatest elongation on January 30 and remains bright through the end of the month.
Jupiter's perihelion (closest point to the sun) comes January 20 at 12 UTC. The distance between the sun and Jupiter is now 460 million miles (740 million km).
In January, the morning planets are Mercury and Mars, and the evening planets are Venus, Saturn, Jupiter and Mars. Moon near Venus and Saturn on January 23.
Learn about the trajectory of the green comet - Comet 2022 E3 ZTF - by the renowned astronomer Guy Ottewell. The comet will be closest to Earth on February 2.
What is a variable star? It's a star that brightens and dim in a cycle that might last hours, or weeks, or months, or longer. Astronomers know millions!