Stargazers, amateur astronomer and comet-hunters have been going crazy about Comet NEOWISE, the brightest comet in seven years.
For a few weeks it’s been a sight for sore eyes in the pre-sunrise eastern sky, but today marks its transition to becoming an easy-to-see naked eye sight in the far more convenient post-sunset northwestern night sky.
What is Comet NEOWISE?
Officially designated C/2020 F3, Comet NEOWISE (named for the NASA infrared space telescope that discovered it on March 27, 2020) has been falling toward the Sun for more than 3,000 years, and passed just 27.4 million miles from the Sun—inside the orbit of Mercury—on July 3, 2020.
It’s now fading slightly as it exits the Solar System, though since it’s getting slightly closer to Earth, it ought to remain relatively bright for a while yet. Comet NEOWISE actually gets closest to Earth on July 23, 2020, when it will be 64 million miles distant.
How to see Comet NEOWISE
Now emerging as a naked eye sight in the evening sky, Comet NEOWISE is probably fading just slightly, so the darker sky you have, the better.
You’re looking for a faint, fuzzy point of light with a fainter, fuzzier tail extending upward from it.
According to Sky & Telescope magazine, you should start looking about 1 hour after sunset, when you’ll find it just over the northwest horizon as the last of twilight fades into darkness. “Look about three fists below the “bowl” of the Big Dipper, which is hanging by its handle high above, and perhaps a little to right,” said the magazine.
The magazine says that July 23—when Comet NEOWISE is at its closest to Earth—will be a good night to observe it. It advises you locate it by first noting the two stars at the bottom of the Big Dipper’s bowl. Then draw an imaginary line through them and toward lower left to a point in the sky a little more than one fist away.
Bob King has written an excellent Comet NEOWISE spotter’s guide on Sky & Telescope, which I urge you to check-out.
How to photograph Comet NEOWISE
Although it may just be possible to photograph Comet NEOWISE with some very new smartphones, plan to use a “proper” DSLR camera on a tripod. You’ll need a long lens.
Set the camera to manual and fix the lens to infinity focus (look for the ∞ symbol on the dial) and around f8-f10 aperture.
Set to ISO 800 or ISO 1600 and experiment with different exposures of around 2-15 seconds.
If the image is really faint, you could experiment with stacking images using image-editing software.
Why does Comet NEOWISE have a tail?
A stream of dust and gas, Comet NEOWISE’s tail is caused by the heat of Sun affecting the comet’s solid nucleus. Its tail is about three miles across, and looks great in a pair of binoculars, though which you can also see the center of the comet’s nucleus—its coma—and a cloud of dust and gas around it.
Originally posted at :forbes