September 29, 2022: Mars approaches the Crab Nebula before daybreak. The crescent moon is with the classic Scorpion after sundown.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:46 a.m. CDT; Sunset, 6:36 p.m. CDT. Check local sources for sunrise and sunset times for your location.
An hour before sunrise, Mars continues its eastward march in Taurus, near the Bull’s horns. The planet is beginning to slow its eastward trek to reverse its direction in about a month. This morning, the Red Planet is 5.8° from Zeta Tauri, the southern horn.
Through a binocular, the star and the planet easily fit into the same field of view. An interesting “smudge” of light appears 1.1° to the upper right of the star. It is known as the Crab Nebula, also known as Messier 1 or M1.
Depending on the level of outdoor lighting, the nebula may blend in with the background light or appear as an oval that is only slighter than the sky brightness. At times through a telescope, with a bright moon or near city lights, the nebula can be lost in the night’s lighting.
Charles Messier was not the first to see the Crab through a telescope. While looking for comets, he spotted this small oblong cloud in 1758. It became his first on a list of over 100 objects in the sky that, while they look fuzzy and diffuse like a comet, they are different in that they don’t move compared to the stars. Comets, like the planets, revolve around the sun and appear to move in front of the distant stars. The Messier objects are “fixed” with the stars. They are gas clouds, other galaxies, and star clusters.
On the morning of July 4, 1054, a bright star appeared near the southern horn. The crescent moon was nearby, about 12° to the upper right of the brilliant star. The next morning, the crescent moon, only 9% illuminated, was over 3° to the left of the brilliant sight.
The records of Chinese astronomers show that the brilliant star was visible for nearly two years and during the daytime for a period of time.
In the 1980s, astronomers proclaimed that sky watchers living in the American Southwest recorded the July 5 moon-star pairing in artwork painted on or pecked into rock faces. One of these images is on the bottom of a rock overhang in Chaco Culture National Historic Park. In his book Cosmos, Carl Sagan wrote,” In the American Southwest, there was then a high culture, rich in astronomical tradition, that also witnessed this brilliant new star. From carbon 14 dating of the remains of a charcoal fire, we know that in the middle of the eleventh century some [Ancient Ones], the antecedents of the Hopi of today, were living under and overhanging ledge in what is today New Mexico. One of them seems to have drawn on the cliff overhang, protected from the weather, a picture of the new star. Its relative position to the crescent would have been just as was depicted” (p.237).
Anthropologists think that the citizens of the region did not record events in their rock art. Rather, artists made images that were important to the culture. Sagan’s description is open enough to suggest that the artist did not draw the supernova and the crescent. Yet, from Sagan’s book and television series, in conversations across popular astronomical circles, the Chaco “supernova pictograph” is taken as fact that it was the moon and the supernova of 1054. We should not be is such a hurry to press modern thinking on the cultural contexts of that time.
Today, the star is no longer there, although a telescope sees an expanding patch of gas that may be one of the most important astronomical things in our galaxy, the remains of an exploded star. It is a supernova remnant with a rotating neutron star inside it. The cloud and pulsar do not shine because they are hot. The stellar corpse has a strong rotating magnetic field. When the field rotates, it sends out a stream of light at all wavelengths (ultraviolet to radio waves), making the pulsar wink on and off like a lighthouse and strongly illuminating the shattered remains of the star.
Astronomer Geoffrey Burbidge noted the importance of the Crab Nebula by saying that there are two parts of astronomy – “the astronomy of the Crab Nebula and the astronomy of everything else.”
An hour after sundown, the crescent moon, 18% illuminated, is about 10° up in the southwest. Its night portion is bathed in earthshine, reflected sunlight from Earth’s oceans, clouds, and land.
The lunar crescent appears to be captured by the Scorpion, although the lunar orb is in front of Libra. The Scorpion’s classic claws, Zubenelgenubi and Zubeneschamali, are to the moon’s upper right. Dschubba, known as “the forehead” or “the crown,” is 5.3° to the upper left. The moon appears as if it’s about to be eaten.
Antares, identified as the Scorpion’s heart, is 12.7° to the left of the lunar slice.
The crescent moon appears with Scorpius again next month. By November 24, Antares sets at sunset, reappearing in the southeast during mid-January before sunrise.
At this hour this evening, Jupiter and Saturn are in the eastern sky. The Ringed Wonder, low in the southeast, leads the planet parade westward. Jupiter is low in the east. Mars rises less than four hours after sunset. Around midnight, the three are strung across the sky.
- 2023, December 20: Morning Star, Evening Moon Nears JupiterDecember 20, 2023: Brilliant Venus is in the southeast before daybreak. After nightfall the gibbous moon nears Jupiter in the southeast sky.
- 2023, December 19: A Scorpion Fumble, Moon MidwayDecember 19, 2023: Before sunrise, Venus appears below the Scorpion’s claws. After sundown, the moon is nearly midway from Saturn to Jupiter.
- 2023, December 18: Pinched VenusDecember 18, 2023: Look for Venus between the Scorpion’s claws in the southeast before sunrise. The thick crescent moon is in the evening sky with Jupiter and Saturn.
- 2023, December 17: Celestial PairsDecember 17, 2023: Before sunrise, Venus passes Zubenelgenubi, a planet-star conjunction. After sundown, Saturn and crescent moon are paired, a planet-moon conjunction.
- 2023, December 16: Venus Clawed, Evening Crescent Nears SaturnDecember 16, 2023: Before daybreak, Venus is above the Scorpion’s southern claw. After nightfall, the crescent moon nears Saturn.