Where to see the once-in-recorded-history green comet approaching San Antonio
The world is buzzing with news of an approaching astronomical body, Comet C/2022 E3 (ZTF), more often referred to in the news and social media as "the green comet." Its most recent appearance was 50,000 years ago — compared to the about 200,000 years since modern humans emerged.
"While the pictures of it have been impressive, its visual appearance differs greatly," explains Joe Wheelock, public program specialist at the McDonald Observatory at the University of Texas at Austin. "Currently you might glimpse it with the unaided eye as a fuzzy patch of light[,] but you would need to be away from city lights. Binoculars or a telescope would improve the view, and you might even glimpse a faint tail."
As tempting as it is — and as much fodder as its made on social media — this experience will not be easy for most Texans to photograph and share. "The pictures that have been posted on various websites were taken by experienced astrophotographers and in most cases cameras designed for astrophotography," Wheelock warns.
Some logistics to note when planning a viewing:
- The comet will be closest to Earth (thus, likely the most visible) on February 1.
- Wheelan says placement will also be good in late January and early February, and it will be best viewed after midnight. Since the new moon was on January 21, every day the moon will compete with it a little more.
- The McDonald Observatory posts daily stargazing tips, so viewers will have a few chances at seeing something special, even if the comment doesn't work out.
- Getting out of San Antonio is the best bet against light pollution.
Those who are willing to make a trip out of the once-in-a-lifetime opportunity should consider their best chances at out running the city lights. The closest popular option to San Antonio proper is McAllister Park, which sometimes hosts stargazing events. For a more structured approach, the Curtis Vaughan Jr. Observatory at the University of Texas at San Antonio hosts first Friday stargazing nights after sunset. The McDonald Observatory, although it is an entity of the University of Texas at Austin, is in Fort Davis, about 400 miles from San Antonio.
The International Dark-Sky Association (IDA) maintains records of some of the world's least light-polluted skies and works to protect them, ensuring that these places stay available for reliable stargazing retreats. There are four IDA-certified Dark Sky Parks in Texas: Enchanted Rock (90 miles from San Antonio), South Llano River (120 miles), Copper Breaks (370 miles), and Big Bend Ranch (490 miles).
In addition to the certified parks, there is a smaller group of Dark Sky Sanctuaries, which are especially dark and carefully protected. There are two in Texas: Devil's River State Natural Area (170 miles) and Black Gap Wildlife Management Area (390 miles).
For more in-depth reading on the comet's trajectory and context, Wheelan suggests an article in Sky & TelescopeSky & Telescope.