A new comet is starting to make an evening appearance in the night sky. A well known comet hunter named David Levy likes to say that comets are like cats, they have tails and they do whatever they want. Expectations for this comet are high and it might live up to those expectations.
Comets orbit the Sun and this comet, Tsuchinshan-ATLAS, or Atlas 3 for short, has moved from being visible in the southern hemisphere in the mornings to being visible in the evening skies in the northern hemisphere. Finding comets can be challenging because they are best seen while they are close to the Sun, but the Sun is bright. But we will have a much brighter planet near the comet and that could make finding it easier.
Comets are often referred to as dirty snowballs. They are made up of frozen ice and dust. As they get close to the Sun they thaw and spew the ice and dust into space. Then the solar wind blows that ice and dust away from the Sun. Because of that, a comet’s tail will always point away from the Sun. As we look for this comet remember that the tail will be extending up away from the western horizon, and since the comet is just now coming around from its passing by the Sun, it will be low on the horizon.
Right now the planet Venus shines brightly in the evening twilight. It is easily seen in the southwestern skies. We can use Venus as a guide to Atlas 3. This sky chart shows the path of Atlas 3 from night to night and it shows the location of Venus. The comet will be brighter while it is closer to the Sun and the western horizon, but for the next few days it will set in twilight. As the comet gets farther from the Sun it will appear higher in the sky, but it will slowly dim in brightness as it drifts higher into the night sky.
The best view you will have of this comet will be with binoculars. First locate Venus and then look to the right, the north, of Venus for Atlas 3. Sweep the sky with your binoculars and you should be able to see the comet. The nucleus of the comet will be the brightest part of the comet and the tail will be extending up from the horizon. Start looking for the comet beginning around 7:30 p.m. It will still be low on the horizon but later this week it will be higher in the sky.
Atlas 3 could be the brightest comet to make an appearance since Hale-Bopp in 1997. But will this happen? Well, comets are like cats, they have tails and they do whatever they want.
