Editor’s note: Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news of amazing discoveries, scientific advances, and more.
The newly discovered comet will occasionally be visible as it passes by Earth next week. But discovering it will require some knowledge.
Japanese space photographer Hideo Nishimura first noticed the comet in early August when he was taking pictures of the night sky, according to EarthSky.
Since then, the celestial body has increased in brightness as it travels through the inner solar system in orbit around the sun.
The comet will reach the closest distance to Earth on Tuesday, when it will reach a distance of 78 million miles (125 million kilometers), which means that it is likely to be seen within the next five days.
It will get very close to the sun, passing within 21 million miles (about 34 million kilometers) of the star on Sept. 17, according to Alan Hale, co-discoverer of Comet Hale-Bopp and founder and chair of the Earthrise Institute.
Nishimura completes one cycle approximately every 430 to 440 years, “which means that the last time it passed near the sun (and may have approached the Earth) was around 1590, before the invention of the telescope,” says Dr. Paul Chodas. the director of NASA’s Center for Near-Earth Object Studies at the Jet Propulsion Laboratory in Pasadena, California, wrote in an email. “We don’t know if it became bright enough to see with the naked eye at that time.”
No comets were recorded during that time frame and they appeared to correspond to Nishimura, Hale said, but they had to be very bright to be seen.
Chodas said the comet is barely bright enough to be visible from Earth due to the distance and will be moving close to the horizon, so binoculars are the best way to see it. The dark sky, away from the city lights, provides an ideal view.
Sky and Telescope have shared charts that could help skywatchers spot the comet.
If you’re trying to distinguish a comet from other objects in the night sky, said Dave Schleicher, an astronomer at Lowell Observatory, keep in mind that a comet’s tail will always point away from the sun because sunlight is constantly pushing away tiny dust particles. in Arizona.
Schleicher said that while the comet appears green in the images due to the presence of diatomic carbon, it will appear almost colorless or slightly pink through binoculars, as sunlight reflects off dust grains, which are smaller than talc particles.
Manuel Romano/NurPhoto/Getty Images
Comet Nishimura can be seen as a faint green dot in the sky over L’Aquila, Italy, on September 7.
For those living in the Northern Hemisphere, Chodas recommends getting a clear view of the eastern and northeastern horizon about half an hour before morning twilight. You can use the time and date to determine when the morning twilight, also called civil twilight, occurs in your area.
He said: “Every day this week, the comet gets a little closer to the sun, the time window becomes narrower, and the comet gets closer to the horizon.” “It won’t be easy to see this comet, unless you’ve observed comets before.”
The closer the comet is to the sun and the horizon, the more difficult it is to see it.
On Wednesday, the comet will pass between Earth and the sun.
“Theoretically, it might be possible to reach it in the evening sky in a few days after that, but it will still be very close to the sun in the sky and will be buried in the bright twilight,” Hill said. “Unless it becomes brighter than expected, it will most likely not be visible.”
Given how close Comet Nishimura is to the Sun, it is possible that the extreme heat could destroy it.
“As the frozen ice heats up and turns into gases, the comet may disintegrate,” Chodas said. “It depends a lot on the size of the nucleus, which we don’t know, since it’s surrounded by a ‘coma’, which is an atmosphere of gas and dust.”
But given that the comet has already survived at least one close approach to the Sun, and likely more than that (although the comet’s age is unknown), Hale and other experts expect it to survive.
“If it survives its passage near the sun, it will pass to the far side of the sun from Earth in early October, and then appear in the southern hemisphere morning sky in November,” Hill said. “It may remain visible for many months after that, although it will likely be a fairly dim object, and will continue to fade as it recedes from the Sun and Earth.”
After that, it will be more than 400 years before the comet passes close to Earth again.
If you miss out on Comet Nishimura, Hale said, many more comets are expected to appear in the night sky over the next 16 months.
Comet Pons-Brooks will be closest to the sun in April, he said, and should be dimly visible to the naked eye in the evening sky for about a month or so before that. In June, Comet Olbers will come close to the Sun and can be seen with binoculars. Discovered in January, Comet Tsuchinshan-Atlas will be closest to the Sun in late September 2024 and will swing close to Earth in mid-October 2024, with the potential to become very bright.