How To See A New Comet This Weekend — Before It Disappears For 435 Years

Stargazers take note: You’ll soon have a few chances to see a newly discovered comet as it passes Earth on its orbit of the Sun.

The comet, C/2023 P1 or simply Comet Nishimura, will pass Earth on September 12, 2023. It will be 78 million miles from Earth at that time and should be bright enough to see with the unaided eye beginning before dawn September 8, according to EarthSky.

The comet will then reach perihelion — its closest point to the Sun — on September 17.

You won’t want to miss the comet as it passes Earth, however. Astronomers calculate that Comet Nishimura’s orbit of the Sun takes 435 years.

All About Comets

Comets can be thought of as a giant snowball made of frozen gasses with embedded rock and dust particles, NASA explains. They typically are roughly the “size of a small town.”

As a comet nears the Sun, it warms up and its ice begins to change from a solid to a gas. This produces what’s known as a “coma,” which is the fuzzy-shaped cloud surrounding the ball of ice. The coma can be thousands of miles in diameter.

Then, radiation pressure — or solar wind — “blows” the expanding coma out to form the long tail that gives comets their distinctive shape.

The New Comet

Amazingly, the new space object was discovered by Japanese amateur astronomer Hideo Nishimura on August 12, while he was taking pictures of the night sky, Space.com explains. The object was then officially confirmed and named comet C/2023 P1 on August 15 by the Minor Planet Center.

Astronomers divide months in half — days 1 to 15 and days 16 to a month’s end — in what’s known as “half-months” to name newly discovered solar-system bodies such as comets and asteroids. These half-months are then labeled as the successive letters of the alphabet. Early January, for instance, is “A.”

The new comet’s 2023 P1 name designates that it was discovered in 2023, in the first half of August, and that it was the first such object discovered in that time period. It is commonly called Comet Nishimura to recognize its founder.

How To See The Comet

The good news is that Comet Nishimura continues to be brighter as it nears Earth.

While the comet will be its closest to Earth on September 12, astronomers believe it should be visible to the unaided eye beginning September 8, SpaceSky explains.

Now, for the bad news, while the comet is expected to be visible about 90 minutes before sunrise, it may be challenging to see just above the eastern horizon due to glare from the impending sunrise, EarthSky notes. The comet will be a little more difficult to spot each morning after September 8.

That said, here’s how to look for Comet Nishimura on September 8 and for mornings after that: Look for the comet before dawn above the eastern horizon. Comet Nishimura will be near the Moon and Venus.

If you’d like some visual aids, the Star Walk 2 app, the Sky Tonight app, and illustrations of the night sky on EarthSky can help you determine where to look in the predawn sky, as well as what you should look for.

Finally, as is always the case with stargazing, your chances of seeing the comet will be better if you are far away from city lights and have an unobstructed view of the eastern horizon.