Time to break out the binoculars. NEOWISE, a comet from the most distant part of our solar system, is temporarily passing through Earth’s orbit, and scientists say it won’t be back for another 6,800 years.
Officially called Comet C/2020 F3 NEOWISE, the comet is named for the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission that first spotted the object on March 27, according to a statement released by the National Aeronautics and Space Administration. The mission uses an infrared-wavelength astronomical space telescope to provide NASA scientists with information about near-Earth objects, like comets and asteroids, that could potentially impact Earth.
“In its discovery images, Comet NEOWISE appeared as a glowing, fuzzy dot moving across the sky even when it was still pretty far away,” NEOWISE principal investigator at the University of Arizona Amy Mainzer said in a statement. “As soon as we saw how close it would come to the Sun, we had hopes that it would put on a good show.”
While NEOWISE was mainly visible before sunrise for most of last week, the comet is now best seen in the evening. Observers may be able to spot the comet in the northwestern horizon shortly after sunset, depending on local conditions. The comet’s central core, or nucleus, is visible with the naked eye in dark skies, but using binoculars can help sky-gazers get a better look at the fuzzy comet and its tail.
Sky-gazers at lower latitudes will see NEOWISE lower in the sky, while the comet will appear higher for observers farther north.
NEOWISE will make its closest approach to Earth on July 22, passing at a distance of 64 million miles, before eventually crossing outside Earth’s orbit on the way back by mid-August. It’s unclear, however, how long the comet will be remain visible, officials said.
The temporary visitor has been spotted by viewers all over the world, as well as from the International Space Station. NASA astronaut Bob Behnken shared photos of NEOWISE from the station last Sunday.
Scientists say the comet is about 3 miles wide, and appears to have two tails — one created by dust coming off the nucleus and another made of gases that have been ionized by losing electrons in the sun’s light.
“[W]e can tell that the comet’s nucleus is covered with sooty, dark particles left over from its formation near the birth of our solar system 4.6 billion years ago,” Joseph Masiero, the NEOWISE deputy principal investigator, said.
The comet made a close approach to the sun on July 3, cruising just inside Mercury’s orbit, according to the NASA statement.
“This very close passage by the Sun is cooking the comet’s outermost layers, causing gas and dust to erupt off the icy surface and creating a large tail of debris,” NASA officials said. “And yet the comet has managed to survive this intense roasting.”
Abigail Feldman can be reached at email@example.com.