Appearing near Earth after nearly 50,000 years, a recently discovered green comet named C/2022 E3 (ZTF) is estimated to come close to us around February 2. The comet was named to refer to those who first spotted it – astronomers using the wide-field survey camera at the Zwicky Transient Facility (ZTF) in the US, in March 2022. NASA has said the comet could be visible with telescopes and binoculars, and might even be visible to the naked eye under a clear night sky. The green colour of the comet is thought to arise from the presence of diatomic carbon – pairs of carbon atoms that are bound together – in the head of the comet. Comets, which fall under the category of long-period comets, take more than 200 years to orbit the Sun, and this comet has a highly elliptical orbit. It will head back to the Oort cloud and make its next appearance roughly 50,000 years later.
Today: December 10, 2023