- Comet Nishimura appears in the night sky this weekend, before skimming past the sun.
- The green comet may even become visible to the naked eye as it grows brighter.
The green-tinged Comet Nishimura is zipping past Earth, and you have a few days to grab what could be a one-time-only chance to spot it — with a little know-how.
Comet Nishimura, named after the amateur astronomer who first spotted it in August, passes closest to Earth on September 12, when it will be about 78 million miles away — roughly 325 times farther than the moon.
Experienced stargazers can see it with binoculars now. In mid-September, as it comes closer, it may even be visible to the naked eye.
You need to be somewhere with dark skies, but it could be well worth the trip, as this may be humanity's only chance of seeing the cosmic spectacle.
After passing our planet, Comet Nishimura will continue careening toward the sun — and possibly its own destruction.
On September 17, it's set to pass within 21 million miles of the sun, according to Space.com. That's about 40% closer than the planet Mercury.
The sun might burn the comet up, making us the first, last, and only humans to ever see it.
But if the ball of space ice survives its fiery flyby, it will reappear in the Southern Hemisphere at the end of September, according to The Planetary Society.
Here's how you can see it for yourself.
How, when, and where to spot Comet Nishimura
For now, Comet Nishimura is only visible in the Northern Hemisphere. Spotting it requires good conditions and a bit of know-how.
"It isn't a peoples' comet," Dan Bartlett, a California astrophotographer who has been photographing comets for years, told Insider via email. "I wouldn't camp out for this one unless you are with an expert in comet observing."
You'll need a spot with dark skies far from any cities, an unobstructed horizon to the East, a pair of binoculars, and ideally a phone application for spotting night-sky objects, like Sky Safari.
Bringing a telescope will give you an even clearer view. You may want to bring a chair for comfort.
The comet may still be visible Saturday morning, but by Sunday Bartlett thinks it could be lost in the glare of the rising sun, too hard for amateurs to spot. Other forecasts have said that Comet Nishimura could get brighter as it approaches Earth through September 12 — possibly bright enough to see with the naked eye — but it will also hug closer to the horizon.
After September 13, it probably won't be visible anymore, according to the Planetary Society.
The comet should be visible just above the Eastern horizon an hour or two before sunrise, between the constellations Cancer and Leo. It shouldn't be too hard to find its general location, since the comet will rise near Venus, which appears as the brightest "star" in the sky.
Look for a "bright, fuzzy head" with "a short, westward-pointing tail," Bob King of Sky and Telescope wrote in a blog post on Wednesday. King said he could see it with a pair of 10x50 binoculars.
Because the comet will appear faint without a telescope, you may be more likely to spot it in your periphery than in the center of your vision.
The comet's head — surrounded by a cloud of gas and dust from the sun vaporizing its ice — is a "pleasing blue-green color," King added.