Comet Neowise, which is about as close to Earth as it ever gets, might well return someday. It just could take about 7,000 years to make the return trip.
And that’s one argument for making an effort to see a visitor from the very origins of the universe before it passes from view, perhaps by the end of next week, said Derrick Pitts, the Franklin Institute’s astronomer.
“You have an opportunity to see a really rare event,” he said. Besides, “we’ve been cooped up inside for a while. This is something you can do as a social distancing activity.”
Neowise just made its closest approach to the Earth, said Frank Maloney, astronomy professor at Villanova University; unfortunately, it appears that clouds and lightning will be a whole lot close Thursday night. Clouds will be a few thousand feet up; Neowise, a few trillion miles.
Conditions should be better from Friday through the weekend, when the clouds will be less abundant and Neowise will appear higher in the sky, although it will be moving farther away.
The viewing may take some effort, since Neowise does not rank high on the brilliance scale, so it is not for the pursuer of cheap thrills. But as Pitts said, “You may never see another one again.”
“A comet is basically a dirty snowball,” said Maloney.
It’s not locally sourced, but it is organic, said Pitts, and it includes carbon dioxide, generous sprinklings of dust, and, scientists have determined, a dash of salt.
NASA researcher Joe Masiero estimates that Neowise is traveling at about 144,000 mph. Its speed would vary along the way, but that rate would come to about 1.2 billion miles a year. Over 7,000 years, that’s a lot of travel without rest stops.
Unlike famous predecessors like Halley, Kohoutek, and Hale-Bopp, which honored their human discoverers, Neowise is named for the NASA space-observing system — Near-Earth Object Wide-field Infrared Survey Explorer — that discovered it out of the blue March 27.
With space robots out there doing the hunting, comet discovery isn’t what it used to be, said Pitts.
One thing you’ll need is in short supply around here: a reasonably dark sky. And you’ll also want an open viewing area.
The best time would be after 10 p.m. Pitts advised spending about 15 minutes adjusting your eyes to the darkness; if you walk into a dark room, it takes a while for objects to appear.
Look to the northwest, 25 to 30 degrees above the horizon, just below the Big Dipper. That’s where Pitts saw it earlier this week. Scan the skies with binoculars if you have them, and after you spot it, you should be able to find it with an unaided eye.
“As time progresses, the sky will darken, but the comet will sink toward the horizon,” said Maloney.
You will not need eye protection: Both Pitts and Maloney rank this as a 2 on a 1-to-5 brilliance scale.
While the comet is making its closest approach to Earth, it has been losing brilliance since it had its closest encounter with the sun on July 3.
But it should get progressively easier to see the next few nights as it appears higher in the sky.
Pitts said it won’t resemble some of the dazzling photos you’ll find online. They are impressive but likely are enhanced images, more or less products of a cosmic version of Photoshop.
If you can do it, he said, drive an hour or so northwest of the city, where you’re likely to see darker skies, and have less water-vapor interference. Humidity tends to obscure the view of the night sky, and that’s why the Shore often isn’t the best place for sky watchers.