What are some skywatching highlights in January 2023? Some lovely groupings this month include the Moon with Mars, and later with Jupiter, and a close conjunction of Venus and Saturn. The brilliant stars of the Northern Hemisphere’s winter sky are a dazzling sight all month long. And a comet discovered last March makes its closest approach to Earth in January, gracing pre-dawn skies.
At the very beginning of the New Year, a comet pays a visit to Earth. The recently discovered celestial body, designated C/2022 E3 (ZTF), will be closest to the Sun on January 12th and closest to Earth on February 1st and 2nd. The comet may be visible in the night sky for several days.
How bright the comet will shine is difficult to predict. Should the brightness continue to increase, as is currently the case, C/2022 E3 (ZTF) could even be seen in the night sky with the naked eye. It should be visible with binoculars or a small telescope.
When is the best time for a sighting?
According to NASA, the best chance of observing the comet is in the early morning hours when facing north. Ideal conditions for a sighting are at the new moon on January 21st or January 22nd, when the sky is darkest.
The comet is moving in a north-westerly direction as seen from the northern hemisphere. It will come within 160 million kilometers of the sun. The closest distance to Earth will be 42 million kilometers.
Neanderthals may have seen the comet
C/2022 E3 (ZTF) is a long-period comet that transits our solar system approximately every 50,000 years. The last time the comet approached Earth, our planet was in the so-called Ice Age.
In this younger part of the Paleolithic period, some of the earliest Homo Sapiens and some of the last Neanderthals may have seen the comet. However, C/2022 E3 (ZTF) was not discovered until March 2022 by the Zwicky Transient Facility at the Palomar Observatory in San Diego, California.
Comets are notoriously unpredictable, but if this one continues its current trend in brightness, it’ll be easy to spot with binoculars, and it’s just possible it could become visible to the unaided eye under dark skies.
Observers in the Northern Hemisphere will find the comet in the morning sky, as it moves swiftly toward the northwest during January. (It’ll become visible in the Southern Hemisphere in early February.) This comet isn’t expected to be quite the spectacle that Comet NEOWISE was back in 2020. But it’s still an awesome opportunity to make a personal connection with an icy visitor from the distant outer solar system.