BOZEMAN — For the next couple weeks, the northern nighttime sky holds a visual treat that's well worth seeing, according to Montana State University researcher Joe Shaw.

The comet known as NEOWISE "is pretty spectacular," said Shaw, a sky-viewing enthusiast and professor in the Department of Electrical and Computer Engineering in MSU's Norm Asbjornson College of Engineering. "It's bigger and brighter than any comet I've seen since the '90s."

Comet NEOWISE above the Bridger Mountains near Bozeman, Montana. MSU Photo by Joe Shaw.

Resembling a large star with a glowing tail, NEOWISE is a chunk of icy and sooty rock roughly 3 miles wide that has been wandering the solar system for more than 4 billion years, according to NASA. The tail is a result of illuminated dust and ionized gases that are vaporized from the comet's surface as it nears the sun.

While a recent comet had tail more like a dull "smudge," Shaw said, with NEOWISE "it's a long streak. It's really very pretty."

The next week or so offers prime viewing, and the best time to see NEOWISE against a dark sky is between roughly 2 a.m. and 4 a.m. as the comet rises in the northeastern sky, according to Shaw. Starting this week, viewers can also spot the comet shortly after nightfall as it descends in the northwest.

As the comet continues its journey though the solar system, those times and locations will shift, and an online sky viewing tool like Stellarium can help keep track, Shaw said. In general, NEOWISE will appear increasingly higher in the northwest at nightfall. By early August, it will set around 1 a.m. and not appear later in the night.

Getting away from city lights and using an ordinary pair of binoculars helps the comet to visually "pop," Shaw said.

Shaw, the director of MSU's Optical Technology Center, is something of a connoisseur of optical phenomena in the sky, often alerting the MSU community to the occurrence of rare and interesting cloud formations or the aurora borealis. He is the author of a book about viewing unique optical phenomena from airplanes. As a result of his optics research, he also has an unlikely connection to NEOWISE, which is named for the NASA satellite — called Near-Earth Object Wide-field Infrared Survey Explorer — that first detected the comet in March.

While on sabbatical in 2015, Shaw helped to develop a NEOWISE replacement at the Utah State University Space Dynamics Lab. The purpose of both satellites is to detect asteroids or other space objects that could collide with Earth, using optical technology so sensitive that they can spot the equivalent of a human hair on Earth from the International Space Station, according to Shaw.

Luckily, the NEOWISE comet will stay a safe 64 million miles from Earth. "But is sure is putting on a show," Shaw said.

- By Marshall Swearingen, MSU News Service -