A bright comet will be visible in northern skies soon. How to see it.

Comet C/2023 A3 (Tsuchinshan-ATLAS) is rapidly approaching its closest approach to the sun, which may be the closest it comes to our planet.

The comet will reach its brightest at about 36.4 million miles from the sun starting on Sept. 27. But, our best views of the comet will come from early to mid-October, according to Astronomy Magazine .

C/2023 A3 has generated excitement among astronomers and amateur skywatchers because it's a long-period comet , one that takes more than 200 years to orbit the sun. (Short-period comets take less than 200 years.)

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The comet was first observed by the Purple Mountain Observatory on Jan. 9, 2023. It also was spotted by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in South Africa.

Since its discovery, the comet has traveled toward the sun and has reached its perihelion – its closest orbital point to the sun – on Sept. 27. Its closest approach to Earth will be on Oct. 11 or 12, according to BBC Sky at Night . It will still be about 44 million miles away.

Comet C/2023 A3 path

The animated image below shows the path C/2023 A3 will take near Earth. The comet's estimated route into the inner solar system is depicted by the dashed line.

What is a comet made of?

Comets are frozen remnants of dust, rock and ice from the solar system's origin, according to NASA . As they approach the sun, they heat up and release gas and dust, appearing like a glowing orb. Their tails can stretch a few miles to several hundred miles.

Where to look for C/2023 A3 in the night sky

For observers in the Northern Hemisphere, comet C/2023 A3 can be found in the constellation Sextans and will rise one hour before the sun, according to Astronomy.com.

The comet will be best viewed in mid-October, rising up from the western horizon and be visible in the southwestern sky at nightfall, weather permitting. That will likely be its best and brightest appearance until it starts to fade from view by Nov. 7, according to SkyandTelescope.com .

Best times to view the comet

Comets can be unpredictable. Even though C/2023 A3 might be visible with the unaided eye, a good set of binoculars or a small telescope could come in handy.

The comet will be visible in the Northern Hemisphere in the evening, just after sunset, when it is low in the southwestern sky. It will have a short viewing window: The comet's closest approach to Earth and best opportunity to view is on Oct. 12.

What is the meaning of the comet's name?

The International Astronomical Union names comets with a code that looks complicated but breaks down like this:

C=Length of time to orbit sun

The "C" in the code prefix doesn't stand for "comet." Instead, it identifies the comet as a nonperiodic one that takes more than 200 years to orbit the sun.

Other prefixes include:

• P: Periodic (or short-period) comet with solar orbit of less than 200 years.
• A: Asteroid or minor planet that was previously identified as a comet.
• X: Comet whose orbit can't be computed.
• D: Periodic comet that no longer exists or has disappeared.
• I: Interstellar object.

Year of discovery

Next is the year in which the comet was first seen.

Month it was found

The letter/number combination indicates the month of discovery.

• Letter: The IAU divides months into two halves and assigns letters A through Y to identify each. Jan. 1-15 is "A" and Jan. 16-31 is "B," for example. (The letter "I" is not used to avoid confusion with the number 1. "Z" isn't used, either.)
• Number: Shows the order in which the comet was found in the half-month of its discovery.

Accordingly, "A3" identifies C/2023 A3 (Tsuchinshan-ATLAS) comet was discovered in the first half of January 2023.

(Who discovered the comet)

Finally, the comet's discoverer is listed in parenthesis. In this case, it was spotted by the Purple Mountain Observatory on Jan. 9, 2023, and the Asteroid Terrestrial-impact Last Alert System (ATLAS) in South Africa rediscovered it on Feb. 22, 2023. The images are compared to collect data on stars, comets, asteroids and other celestial objects.

CONTRIBUTING George Petras, USA TODAY

SOURCE NASA, Space.com; EarthSky.org, UniverseToday.com, International Astronomical Union, TheSkyLive.com, LiveScience.com, SkyandTelescope.com, USA TODAY Network reporting and research

This article originally appeared on USA TODAY: A bright comet will be visible in northern skies soon. How to see it.