I read the article on the green comet on Jan. 23 and thought some additional information might help readers understand and find the comet that has been in the news lately. My reference is Sky and Telescope magazine. The magazine article has a good chart to show where the comet can be seen in the northern sky during the best observing dates.
To see the comet you will need binoculars to get the best view. A spotting scope or telescope may also be helpful.
The comet is expected to reach a magnitude of 6, which is the faintest object that can be seen by the naked eye. To see an object of magnitude 6 you need dark skies, away from city lights, and you need a clear night with no clouds or fog. Young eyes will help.
My wife Louise just had cataract surgery. Before that she wouldn’t have been able to see the comet.
Having no moon or a thin crescent moon in the sky is also a help. Unfortunately, the moon is now near new moon phase, which mans it will be near full moon when the comet is closest to Earth and likely when it is brightest.
To find the comet, you will be looking north or northeast. If you can find Ursa Major (the Big Dipper is the best known part of Ursa Major), it will help you find the comet. The two stars at the end of the cup of the dipper (not where the handle is but at the far end from the handle) roughly align with Polaris, the North Star.
Because of our latitude here in the Rio GrandeValley, stars in the northern sky appear lower in the northern sky than for much of the state, nation, continent — take your pick.
Objects near the horizon are dimmed by the atmosphere. Looking straight up, the thickest part of the atmosphere is about 30,000 feet or 6 miles thick. Looking toward the horizon, you may looking through 40 or 50 miles of atmosphere.
Using the chart referenced in the article, you will see that on Jan. 30 the comet will be located along a line from the two pointer stars of the dipper to Polaris. Polaris is an easily seen star but not a really bright star. Polaris is the star at the end of the handle of the Little Dipper (Ursa Minor).
By the way, “ursa” is Latin for “bear;” thus the Big Bear and the Little Bear.
The dippers are known as asterisms, not constellations. The chart shows the constellations with lines connecting the major stars in the constellation. The cup of the Big Dipper is a small part of Ursa Major.
When to look: The moon will be setting about midnight on Jan. 30 and the Big Dipper will be well up in the northern sky, a little higher than Polaris. Set your alarm clock for 2 a.m. or a little later, depending on how far you plan to drive to get to really dark skies. You need a location with few streetlights and a clear northern horizon, no trees or large buildings to your north. If you are in or near the bright lights of the city, try to find a public area on the northern edge of the metropolitan area. Sal del Rey National Wildlife Area comes to mind; you may have another place nearer where you live.
If you don’t want to drive, don’t give up — you should be able to see the comet. If your northern horizon isn’t dark, the comet won’t contrast as well with the background light, which will make it a little less impressive.
Notice that I didn’t sat unimpressive, nor did I say spectacular. This is by all estimates going to be a dim comet.
You are not looking for something in the sky whizzing by. The comet’s movement against the background of stars is only noticed over a period of hours. At its closest to Earth you may notice that it has changed position in a matter of a few minutes.
Louise picked up a comment on your Facebook page that questioned how we know the orbit is a 50,000-year orbit. It takes a number of observations over a relatively short period of a comet’s orbit to determine its orbital characteristics. Astronomers have been watching this comet since it was discovered in March 2022.
Fifty thousand years is a good estimate but not an exact figure. The first clue here is all those zeros. You can’t expect to see the comet in 52,023; it will likely be a little earlier or perhaps a little later, so don’t put it on your calendar yet.
Thomas Butler is a retired science teacher and an amateur astronomer living in Edinburg.
