September 30, 2022: Before sunrise, bright Jupiter and Mars are easy to spot. After sundown, the crescent moon is near Antares, the Scorpion’s heart.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:47 a.m. CDT; Sunset, 6:34 p.m. CDT. Check local sources for sunrise and sunset times for your location.
As September ends, daylight has shrunk to 11 hours, 47 minutes, losing 100 minutes during the month.
Here is today’s planet forecast:
An hour before sunrise, bright Jupiter is less than 10° above the western horizon. It sets about 20 minutes before sunrise. Tomorrow Venus and Jupiter are at opposition. Jupiter sets and Venus rises. This occurs during bright twilight. Perhaps neighborhood trees, houses, or other obstructions have already blocked either or both planets from your simultaneous sightings. After tomorrow, the two planets do not appear above the horizon together again until later in the year when Venus enters the evening sky.
At this hour, Mars – slowing its eastward march in Taurus – is high in the south-southwestern sky. It is nearing the Bull’s horns, 5.4° to the lower right of Zeta Tauri – the southern horn.
Through a binocular, the star and the moon appear with the difficult-to-see Crab Nebula – a Rosetta Stone of stellar cycles.
Mercury is quickly moving into the morning sky. In about a week it puts on its best morning display of the year. This morning it rises 63 minutes before sunup and fifteen minutes later, it is a few degrees above the eastern horizon. It might be spotted with a binocular, but it is not bright yet and its brightness is reduced by the dimming effect of our atmosphere for celestial sights near the horizon.
Forty-five minutes after sunset, the crescent moon, 28% illuminated, is low in the southwestern sky. Earthshine is again easy to spot, but the effect is quickly ending as the moon’s phase waxes. The lighting from reflected sunlight dims each evening. It returns again when the moon wanes later next month.
Its easiest to capture earthshine with a tripod-mounted camera and exposures ranging up to a few seconds.
Look carefully for Antares, the Scorpion’s heart, 1.8° to the lower right of the lunar slice. The star’s name means “the rival of Mars.” Both are about the same color and brightness, when the Red Planet passes through this celestial region at intervals that are about 20 days short of two years. The next conjunction of the two celestial wonders is December 7, 2023, although they are too close to the sun for reasonable visibility.
This conjunction is followed by another difficult-to-see grouping on November 18, 2025. The October 30, 2027, conjunction is visible low in the southwest after sunset. Nearly two years later, at the October 7, 2029, conjunction, Antares is about 10° above the southwest horizon at one hour after sunset. Mars is 3.3° to its upper right.
Antares is 4° south of the ecliptic, the plane of the solar system and the imaginary circle around the sky where the planets generally appear. Mars does not have close conjunctions with the bright supergiant star. The Red Planet’s orbit is tilted 1.8°, only slightly different from the plane that is aligned with Earth’s orbit.
Fifteen minutes later this evening, bright Jupiter is about 10° up in the eastern sky. Just four evenings after its opposition with the sun, the Jovian Giant is the brightest star in the sky at this hour. Not many compete with its brightness, only Venus is brighter. On occasions, Mars is brighter when it is near opposition, but not this year with the Red Planet’s farther distance when our planet passes by.
Jupiter is in the sky all night long, only setting a few minutes before sunrise. After midnight it is high in the south, with Mars in the east and Saturn toward the southwest.
This evening Saturn is less than one-third of the way up in the south-southeast, near the stars Deneb Algedi and Nashira in eastern Capricornus. The planet continues its retrograde as it approaches Iota Capricorni (ι Cap). This dimmer star is visible for sky watchers living away from bright outdoor lighting. From urban and suburban skies, a binocular is needed to see it 1.0° to the right of the Ring Wonder.
During the next three weeks, Saturn’s westward tempo slows as it appears to turn eastward again. It cuts the distance in half, about the diameter of the Full moon, during that period.
March 2, 2023: Venus opens a gap on Jupiter in the west-southwest after their conjunction last night. The moon is near Pollux after sundown. Mars marches eastward against Taurus.Keep reading
February 28, 2023: One night before their close conjunction, Venus approaches Jupiter in the west-southwest after sundown. The moon is near the horns of Taurus with Mars nearby.Keep reading