A space-born visitor, the Neowise comet, is dazzling skygazers this month.
The brightest comet to grace our skies in nearly a quarter century is visible in the Northern Hemisphere through mid-August. The celestial guest will make its closest approach to Earth on July 23 at a distance of 64 million miles—about equal to Mercury’s average distance from Earth.
People can view the comet, officially, C/2020 F3 (NEOWISE)—with the naked eye in the northwest skies. The comet will appear all night under the Big Dipper constellation.
Each evening the comet climbs higher in the sky until eventually it fades from view. The space-rock is expected to return again in 6,800 years.
In addition to its nighttime show, Neowise is temporarily visible for early risers in the morning too. Look to the northeast about an hour before sunrise for the telltale trailing tail, which will slip beneath the horizon and out of view in the coming days.
Visit NASA.gov for additional observational details, or Sky & Telescope magazine. People can also enter their locations into a helpful online app developed by a NASA volunteer to determine the best viewing opportunities.
What do we know about the Neowise comet?
Neowise is a hurtling, dusty ball of ice that’s as old as the solar system at 4.6 billion-years old.
The 3-mile-long space icicle is believed to have originated in a region of outer space called the Oort Cloud. The cloud is a graveyard of frozen rocky fragments leftover from the formation of the planets, and it exists far past the orbits of Neptune and Pluto.
Despite its age, scientists discovered Neowise only very recently. NASA astronomers detected the snowball on March 27 using a space telescope, also called NEOWISE, the comet’s namesake. (The name stands for Near-Earth Object Wide-field Infrared Survey Explorer.)
NASA uses NEOWISE, the telescope, to hunt for celestial objects that could endanger Earth. One such missile—the Chicxulub impactor, named for its collision site in present-day Mexico—is believed to have annihilated the dinosaurs 65 million years ago.
“We want to spot objects like Comet Neowise well before they can make any close approaches,” Amy Mainzer, principal investigator for the NEOWISE project and professor of planetary sciences at the University of Arizona, said in an email to Fortune. She notes that this one is “very large, about as big as the object that wiped out the dinosaurs,” but that it fortunately “poses no hazard.”
By studying comets like Neowise, scientists hope to learn more about the solar system’s origins—and avoid potential extinction “We need to know what comets and asteroids are made of and how crumbly they are—or solid—if we ever have to push one out of the way,” Mainzer says.
What does the comet look like?
To the naked eye, Neowise will appear as a fuzzy star streaking across the sky.
The comet will be about as bright as the stars appearing close by in the Big Dipper, a constellation also known as Ursa Major, or the Great Bear. While not required, a pair of binoculars or a telescope will enhance the view.
Even astronomers look on in awe. “As a byproduct of these searches, we get to see something really beautiful that reminds us of our connection to the larger universe.,” Mainzer says.
Neowise, like most comets, has two tails that extend for millions of miles. The first, made of dusty debris, shines golden as it reflects sunlight. The second tail, made of electrically charged gas particles blasted by solar radiation, glows faintly blue toward the left.
The last time a comet blazed this intensely from our earthly vantage point was during the Hale-Bopp Comet’s visitation in the mid-’90s.
Infamously, 39 members of the Heaven’s Gate cult committed ritual suicide in a San Diego suburb during the astronomical event. They believed doing so would enable them to hitch a ride on an accompanying extraterrestrial spacecraft.
Photos of the Neowise comet
Neowise made its closest approach to the sun on July 3. The comet is now swinging back out into space, propelled by our star’s gravitational slingshot.
Unlike Neowise, most comets present no spectacular show. Comet ATLAS and Comet SWAN, also discovered earlier this year, fizzled out during their cosmic circuits.
The most famous comet, Halley’s, is an anomaly. It is the only known, reliably visible comet with a short enough period to be witnessed in the span of a lifetime. (Mark your calendar for the next appearance: July 28, 2061.)
More commonly, comets are unpredictable and capricious; there’s no knowing exactly when the next one will gleam. So photographers and astronomers of all stripes are jumping at the opportunity to capture the beauty of Neowise’s sojourn.
Here is a sampling of our favorites.