Follow Comet E1 Atlas Through the July Sky

Comet C/2023 E1 ATLAS passes the northern pole for summer northern hemisphere observers.

When it comes to comets, even the best guesses can often betray the truth. Bright comets can break up as they approach the Sun, and fainter comets that usually don’t warrant a second glance often burst into view.

Fortunately, the former seems to be the case with comet C/2023 E1 ATLAS, which is exceeding expectations of late, and recently brightened in the range of binocular visibility at magnitude +10.

To be sure, the comet will probably top +8^th at +9^th magnitude through July as it reaches perihelion just outside Earth’s orbit this coming weekend. The comet is well placed in the night sky for northern hemisphere campers through Canada Day on July 1^St and Fourth of July weekend.

A Unique Orbit

Comet C/2023 E1 ATLAS was discovered by the Asteroid Terrestrial-Impact Last Alert System (ATLAS) station based in Sutherland, South Africa on the evening of March 1^St2023. At that time, the comet was faint +19^th magnitude object, gliding through the constellation Virgo.

The comet’s orbit is an interesting one, with a 38 degree inclination relative to the ecliptic. In just an 85-year orbit, the comet reached aphelion in early 2066 at 37.7 Astronomical Units (AU) from the Sun, just outside the orbit of the planet Neptune. In fact, the planet seems to share a 2:1 orbital resonance with the comet, as it completes two orbits each for Neptune. Although the comet currently has a ‘C’ designation for a long-period (as opposed to periodic) comet, that is likely to change, as 85 years is less than the 200-year orbital period cutoff that defines two categories.

The 2023 Apparition for Comet E1 ATLAS

It’s rare to see a new short-period comet of note; most major ones like 1P/Halley or 2P/Encke have been found over the centuries. July is the key month for comet E1 ATLAS, as it begins at full moon in the north in the constellation Ursa Minor, and crosses Draco and heads toward Cepheus on its way to closest approach to Earth in mid-August. This favorable 2023 appearance may be why the small comet has eluded detection for so long.

Comet E1 ATLAS Through July and August

Here are the main celestial dates with a destiny for Comet C/2023 E1 ATLAS:

July 1st^St – Reach perihelion, at 1.027 AU from the Sun.

(Full Moon July 3rd)

July 8^th – Reach the highest northern declination, just nine degrees from the north celestial pole.

July 9^th – You pass by more than one degree from the +4.2 magnitude star Epsilon Ursa Minor.

(Last Quarter Moon July 10th)

July 14^th – Cross the constellation Draco the Dragon.

(New Moon July 17th)

(First Quarter Moon July 25th)

July 29^th – Cross the constellation of Cepheus the King.

(Full Moon August 1st)

August 1^St – Drops back below +10^th magnitude?

(Last Quarter Moon August 8th)

August 9^th – Cross the constellation of Cepheus.

August 10^th – Crossing the galactic equator southward.

(New Moon August 16th)

August 18^th – Passes closest to Earth, at 0.375 AU away.

August 22^n.d – Cross the constellation Pegasus

(First Quarter Moon August 24th)

August 29^th – Reached the ecliptic opposition, 180 degrees opposite versus the Sun.

Blame it on the Moon

Unfortunately, the Moon reaches Full phase on July 3^street hampering deep sky observations, Although New phase in the weeks surrounding July 17^th should be fine to track the comet down. Look for the comet as a small ‘fuzzball’ like a globular cluster that stubbornly refuses to focus.

If you get a chance, be sure to check out C/2023 E1 ATLAS… Remember, comets often don’t read the predictions, and the achievement may exceed expectations!