October 21, 2022: The morning crescent moon is in the eastern sky before sunrise, seemingly in the belly of Leo. Arcturus is visible in the eastern sky before sunrise and western sky after sunset.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:10 a.m. CDT; Sunset, 6:00 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Here is today’s planet forecast:
An hour before sunrise, the crescent moon, 16% illuminated and showing earthshine, is over one-third of the way up in the east-southeast. It appears to be in the belly of the Lion, about halfway from Regulus and Denebola.
Leo is a westward facing Lion, seen in silhouette, climbing into the eastern sky before sunup. The head is outlined by a backwards question mark or sickle shape. Regulus – meaning “the prince” – is at the bottom of the shape in a place that dots the heart. The animal’s haunches are outlined by a triangle, tipped by the tail, Denebola.
The night portion of the moon is gently illuminated by sunlight that is reflected from Earth’s oceans, clouds, and land. From the moon Earth is approaching the full phase, while earthbound sky watchers see a thin lunar crescent.
Farther westward, Mars is slowing its eastward march in front of Taurus. Find the Red Planet high in the southwestern sky. The planet is brighter than all the stars in the immediate region, but it is slightly dimmer than Sirius.
In about a week, Mars seems to reverse its direction, beginning to move westward or retrograde compared to the starry background. This illusion is from Earth slowly overtaking Mars that revolves around the sun at a greater distance. The line of sight from Earth to Mars that is extended to the stars normally moves eastward. As Earth moves inside Mars, the line of sight reverses its direction and Mars seems to move westward or retrograde, an illusion.
This morning Mars is above an imaginary line that connects the Bull’s horns, Elnath and Zeta Tauri. The animal’s head is outlined by the Hyades star cluster and Aldebaran. The Pleiades rides on the back.
Mercury is racing back into morning twilight. At forty minutes before daybreak, the speedy planet is only 4° up in the east-southeast. It is brighter than Mars, but dimmer than Sirius. It is visible at a clear horizon and attention called to it here because of its visual intensity. To locate the planet, it is near the horizon, below and slightly to the left of the moon.
Arcturus is making its first morning appearance. It is slightly higher than Mercury and above the east-northeast horizon.
Two bright planets are in the southeast after sunset. Saturn is about one-third of the way up in the south-southeast. It is near two dimmer stars – Deneb Algedi and Nashira – in eastern Capricornus. The planet is nearing the end of its retrograde track in two evenings.
Jupiter is that “bright star” in the east-southeast. Earth was between the planet and the sun last month. The sun and planet were in opposite directions, known as opposition. The Jovian Giant is retrograding in front of a dim starfield in Pisces. The planet’s relative motion compared to the stars is not easily observed like Saturn or the rapid march of Mars compared to Taurus.
Early in the evening look westward. While Arcturus is making its first morning appearances, it is still in the west after sunset. It is part of a kite-shape constellation known as Boötes. Arcturus can be identified by locating the Big Dipper, now low in the northwest. The dipper’s curved handle points toward the bright star. In the morning, the dipper stands on its handle in the northeast.
Unlike other stars that are more southerly, Arcturus can be visible in the morning sky and the evening stellar lineup. The same effect occurs with other bright stars, like Deneb, Vega, and Capella.
The more southerly stars, such as Sirius, Procyon, Spica, Aldebaran, Regulus, and others, make their first morning appearances. Each morning they appear higher in the east before sunrise. Within a few months, they are farther westward and then they enter the early evening sky. Several months after their first morning appearances they disappear into the bright evening twilight in the western sky, to repeat the pattern again.
During the night, Saturn leads the bright planet parade westward. Before midnight, Jupiter is about halfway up in the south. Mars is low in the east-northeast and Saturn is low in the southwest. The three bright outer planets are strung along the plane of the solar system.
This planet display appears earlier in the evening as the autumn season progresses. Venus and Mercury move into the evening sky late in the year, making another five-planet display. From the sunset point eastward the planet order is Venus, Mercury, Saturn, Jupiter, and Mars.
- 2023, October 20: Jupiter’s Double Shadows, Mercury at Superior ConjunctionOctober 20: After midnight, Jupiter’s moons’ shadows dance across the cloud tops. Mercury is at superior conjunction.
- 2023, October 19: Poured Moon, See Planet UranusOctober 19: Sagittarius seems to pour the moon into the sky this evening. Find Uranus with a binocular.
- 2023, October 18: Moon-Antares Conjunction, Bright PlanetsOctober 18, 2023: The moon is near Antares after sunset. Venus, Jupiter, and Saturn are in the sky during the nighttime hours.
- 2023, October 17: Scorpion MoonOctober 17, 2023: The crescent moon is with Scorpius during evening twilight. Venus and Jupiter gleam from the predawn sky.
- 2023, October 16: Venus in Starry ConjunctionOctober 16, 2023: Venus passes a star in Leo before sunrise. A crescent moon is low in the western sky during evening twilight.