by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:11 a.m. CDT; Sunset, 7:33 p.m. CDT. Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.
Summaries of Current Sky Events
Here is today’s planet forecast:
Earth passes between Saturn and the sun this morning at 3:28 a.m. CDT. Astronomically, this is known as opposition, with the planet nearly 815 million miles away. These two celestial objects are 180° apart in the sky. Saturn sets this morning as the sun rises.
Saturn is the slowest-moving of the five bright planets, although the worlds and other bodies farther from the sun revolve slower. The Ringed Wonder revolves around the sun in nearly thirty years.
Earth now moves past the sun-Saturn imaginary line and quickly moves away. Saturn rises before sunset each evening and sets before sunup each morning. Earth overtakes Saturn again on September 8, 2024, only thirteen days longer than a year. If you are counting days, remember 2024 is a leap year.
An hour before sunup, three bright planets – Venus, Jupiter, and Saturn – and two dimmer ones – Uranus and Neptune – are along an arc from the east horizon to the west-southwest.
Brilliant Venus, rising nearly eighty-five minutes before daybreak, is low in the east. The Morning Star is sprinting into the sky, gaining seven minutes of rising time compared to sunrise during the next several mornings.
While the planet is near the horizon this morning, it is easy to see along with Sirius that is low in the east-southeast. Venus does not pass closely to the Dog Star, but the brightest planet and brightest star are in the eastern sky at the same time.
Jupiter is high in the south-southeast, brighter than Sirius, but dimmer than Venus. The planet is 13.5° to the lower left of Hamal, Aries’ brightest star, and nearly 16° to the lower right of the Pleiades star cluster, part of Taurus.
Jupiter is slowly moving eastward, although it reverses its direction and begins the illusion of retrograde early next month.
Through a telescope with an eyepiece providing 80x magnification, Jupiter’s globe is easily visible. Look carefully for the cloud stripes that are whipped parallel to the equator. This lineup forms the plane for the planet’s bright moons. Io and Europa are east of the planet, although Io is close to the world. Ganymede and Callisto are to the west.
The distant star Sigma Arietis (σ Ari on the chart) is west of Callisto. Recently, it seems to have been mimicking a new Jovian moon. The star happens to lie far beyond the solar system, about 500 light years away, but nearly in the plane of the moons’ orbital paths. It makes a stationary point of reference as Jupiter moves eastward.
Earlier this morning, at 3:17 a.m. CDT, Jupiter’s Great Red Spot is at the center of the planet in the southern hemisphere. To see this feature a higher magnification eyepiece is needed. Start with 150x or so.
Uranus is nearly between Jupiter and the Pleiades star cluster. Look for it earlier when the sky is darker. It is at the limit of human eyesight, not visible without a binocular’s optical assist. This is not an easy find, especially for those sky watchers who have not used a binocular for celestial viewing. First, find either Jupiter or the Pleiades through the binocular, again, not easy without some practice. Then move the binocular the appropriate direction between these two landmarks. The accompanying chart shows four dim stars, Delta Arietis (δ Ari on the chart), Zeta Arietis (ζ Ari), Tau Arietis (τ Ari), and 63 Arietis (63 Ari). Once they are found, move the binocular slightly so they are near the top of the field of view. Aquamarine Uranus, dimmer than the individual stars in the stellar quartet, is near the center of the field of view. It appears starlike. A telescope is needed to see its globe, tiny at its distance.
During morning twilight, Saturn is the western planet in this five-planet lineup, spanning over 157° eastward to Venus. At opposition, Saturn is retrograding in front of Aquarius. The Ringed Wonder is over 10° above the west-southwest horizon, 8.3° to the lower right of Skat, meaning “the leg,” and 8.2° to the lower right of Lambda Aquarii (λ Aqr on the chart). The planet and the stellar pair nearly make an equilateral triangle.
Neptune is the most difficult to locate in a dim starfield in Pisces. No bright stars are nearby to easily guide us to the planet. Sometimes other bright planets or the moon are nearby to serve as a reference. This does not occur this morning. The most-distant planet in the modern solar system model is over 20° to the upper left of Saturn. Neptune is 0.4° above the nearest star in the binocular field, 20 Piscium (20 Psc on the chart). The planet is considerably dimmer than the stars through the binocular. Considerable telescopic magnification is needed to see Neptune’s globe.
While east of the sun and in the evening sky, Mercury and Mars are bathed in bright twilight. Mercury is nearing inferior conjunction, setting only fifteen minutes after the sun.
Mars, considerably dimmer than might be expected, sets about an hour after sunset. Its solar conjunction occurs during November, followed by a slow climb into the morning sky during early 2024.
After sundown, the bright moon, 87% illuminated, is low in the south-southeast, in front of Capricornus, to the east of Sagittarius. Earlier today in western Australia and Indonesia, the moon covered or occulted the star Tau Sagittarii (τ Sgr on the chart) in the Teapot’s handle. In this bright moonlight use a binocular to trace the pot in the sky.
Nearly twenty-four hours after opposition, Saturn, rising before sunset, is over 10° above the east-southeast horizon at one hour after sundown. This is the beginning of the parade of five bright planets and ends with Venus rising about 90 minutes before sunup tomorrow.
- 2023, October 21: Three Bright Planets, First Quarter MoonOctober 21, 2023: Venus, Jupiter, and Saturn are easy to locate during nighttime hours. The First Quarter moon phase occurs this evening.
- 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.