Throughout December, a once-in-a-lifetime comet will be visible in the sky for most of the month, and is expected to pass closer to Earth on December 12. Comet Leonard, also known as Comet C / 2021 A1, was discovered in early January 2021 and is currently on track to achieve its closest approach to the Sun. The comet, which has a greenish coma, was discovered around the heart. from NGC 4631, better known as the Whale Galaxy. With its closest approach to Earth (and even a closer approach to Venus) yet to come in December, Comet Leonard will become brighter on January 3, 2022, when it is expected to reach the Sun and fly for a million. of years. Later, it will become an interstellar comet, leaving our Solar System behind.
On December 12, when the comet passes closest to Earth, just a few weeks before it achieves its closest approach to the Sun, it is expected to light up and become visible to the naked eye, according to some estimates. While comets are notoriously difficult to predict, Comet Leonard will be visible a few hours before sunrise through the constellations Coma Berenices, Boötes, and Serpens Caput, low in the east-northeast sky. With a small telescope or a pair of binoculars, it will be easy to spot. As it approaches the horizon, it will pass between Arcturus and the handle of the Big Dipper, just at the time of its closest approach to Earth.
Throughout the month, Comet Leonard is best seen in the early morning before sunrise. To find it, you have to look east an hour or two before sunrise. It will rise higher in the sky just before sunrise, but the sky will also be clearer at that time. On December 12, set out at dusk to look for the comet as it passes Venus and Mercury, then Saturn and Jupiter in the southwest.