The last few days to get a good look at Comet NEOWISE are approaching.
The comet, discovered in late March, will be closest to Earth this week. Since it’s already moving away from the sun, it’s not quite as bright as it was earlier this month, and it’s getting dimmer.
To see it in metro Atlanta, astronomer David Dundee from the Tellus Science Museum in Cartersville has a few tips.
1. Get away from city lights if you can, and do it on a clear night
The bright lights of Atlanta will make viewing tough.
“I would recommend if you could find a dark spot with a good view of the northern horizon — you don’t want something with too many tall trees — that’s what you should be doing,” Dundee says. “The suburban sky, downtown Atlanta, may be a little trickier.”
He suggests checking hours at parks that are away from the denser parts of Atlanta, to see if they’re open for nighttime visitors.
If it’s cloudy, try again another night.
2. Bring binoculars, and focus them on the Big Dipper
After dark, between around 9 and 10:30 p.m., look to the North and find the Big Dipper.
Dundee recommends using a star to focus the binoculars.
“If you haven’t had your binoculars looking at something in the sky before, you’re looking at cats or birds or whatever, you need to focus the binoculars for infinity,” he says. “So what you do is find a bright star in the Big Dipper. Then focus your binoculars on that.”
3. Look down from the Big Dipper toward the horizon, and find the comet
Once you’re focused on the Big Dipper, scan down toward the horizon.
“It will look at first like a fuzzy blob in the sky. If you look carefully, you’ll notice that the tail of the comet is extending up from the horizon,” Dundee says.
4. Enjoy looking at “a pretty cool comet”
Dundee says we’ve been in a bit of a dry spell for bright comets. The last really bright one was Comet Hale-Bopp, more than 20 years ago.
“We discover probably about a dozen comets a year, but most of them are just pretty underwhelming, they’re just very faint, and they can seem as a little smudge in the telescope,” he says. “But this one truly is one that anybody can see, and so it’s a pretty cool comet as comets go.”
Up close, Comet NEOWISE, which is about 3 miles across with a tail extending thousands of miles, would look like a very big, very dirty snowball, which is, in fact, pretty much what it is.
“It’s covered with dust. The solar system is kind of a dusty place, and so over billions of years — and these objects are 4 and a half billion years old – they get dusty and dirty,” Dundee says.
As comets approach the sun, they start to get more interesting than your typical grimy snowball.
Their frozen gases begin to sublimate, turning from solid into gas without a stop at the liquid stage. The solar wind blows the comet’s tail away from the sun. (The tail doesn’t tell you which direction the comet is traveling; it tells you where the sun isn’t.) And the comet reflects the light of the sun.
Comet NEOWISE is named after the space telescope that found it, NASA’s Near-Earth Object Wide-field Infrared Survey Explorer.
If you miss seeing it this time around, don’t worry, Comet NEOWISE should be back near Earth in 6,800 years.
For slightly sooner celestial events, Dundee recommends the Aquariids meteor shower later this month, and the Perseids in August. Those have a comet connection, too, he explains. The meteors are dust and ice left behind by comets. When the Earth passes through their orbits, we see the debris as meteors.
“And so you see the remains of comets in the sky all the time,” he says.