This morning’s spectacular sky includes a thin crescent near Morning Star Venus with Mercury and Spica nearby, as the moon dances past the morning planets. Venus continues to shine as “that bright star” in the east before sunrise. In the evening Mars marches is nearing the end of its retrograde motion in Pisces. Jupiter approaches Saturn in eastern Sagittarius as a prelude to the Great Conjunction on December 21, 2020.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:37 a.m. CST; Sunset, 4:32 p.m. CST. Check local sources for sunrise and sunset times for your location.
Morning: As morning twilight progresses, look for Venus and the thin crescent moon in the east-southeast. The lunar slice is only 11% illuminated and it shines 6.5° above Venus. About 45 minutes before sunrise, Mercury – low in the east-southeast – is nearly 13° to the lower left of Venus and about 9° to the lower left of Spica.
Your fist at arm’s length is about 10° across to gauge the Venus – Mercury separation. Holding up your fist – from your thumb knuckle to your pinky finger – to the sky, it fits between Venus and Mercury this morning.
Photographers can record the scene with time exposures up to about 10 seconds. The night portion of the moon is illuminated like the featured image above. This is known as earthshine. Reflected sunlight from Earth’s oceans, clouds, and land gently illuminates the night portion of the moon.
In the starfield, use a binocular to the brilliant planet 0.3° to the lower left of Theta Virginis (θ Vir on the chart above) and 8.4° to the lower left of Gamma Virginis (γ Vir). The binocular also reveals the earthshine on the moon.
Morning detailed note: One hour before sunrise, brilliant Venus – about 18° up in the east-southeast – is 0.3° to the lower left of Theta Virginis (θ Vir, m = 4.4). The crescent moon (26.7d, 11%) is 6.5° above Venus and 2.9° to the lower left of Gamma Virginis (γ Vir). Forty-five minutes before sunrise, Mercury is 12.9° to the lower left of Venus and 8.7° to the lower left of Spica.
Evening: Jupiter and Saturn are in the south-southwest about an hour after sunset. This planet pair is slowly moving eastward compared to the stars, although Jupiter moves quicker than the more-distant planet. The Jovian Giant is slowly overtaking the Ringed Wonder as a prelude to the Great Conjunction on December 21, 2020.
This evening the planets form a triangle with the dim star 56 Sagittarii (56 Sgr on the chart). Saturn is 2.9° to the lower left of the star while Jupiter is 2.9° to its lower right. Use a binocular to see the planets with the dim star.
Jupiter passes impossible-to-see Pluto this evening. The planet requires a telescope with a minimum eight-inch lens or mirror. Additionally, Pluto is low in the sky at the end of evening twilight, raising another challenge to locate the tiny world, even with a large telescope.
(Here we consider Pluto one of the “Classic 9” planets, largely because of its important place in the quest for distant planets in the solar system.)
Farther east, bright Mars retrogrades in Pisces. The planet is slowly as it resumes its eastward march through the stars in a few evenings.
With a binocular find the Red Planet 3.3° to the lower right of Epsilon Piscium (ε Psc on the chart) and 3.2° to the lower left of Delta Piscium (δ Psc). The planet does not seem to move much from this location for a few evenings as the illusion of retrograde ends.
For more about Mars during November, see this article.
Evening detailed note: One hour after sunset, Saturn is nearly 25° in altitude in the south-southwest. Jupiter and Saturn make a triangle with 56 Sgr. Saturn is 2.4° to the lower left of the star, while Jupiter is 2.9° to the lower right. The planets are 4.0° apart with Saturn to the upper left of Jupiter. Farther east, Mars (m = −1.7) is nearly 28° up in the east-southeast. Mars is 3.3° to the lower right of ε Psc and 3.2° to the lower left of δ Psc. At the end of evening twilight, Jupiter, 19° up in the southwest, is 0.6° to the upper right of Pluto, for the third conjunction of Jupiter’s apparition. At the same time, Jupiter is 4.0° to the lower right of Saturn.
Read more about the planets during November.
May 28, 2021: This evening Mercury passes brilliant Venus for the second of three conjunctions during this evening apparition of the second planet from the sun. Use a binocular about 45 minutes after sunset to see the speedy planet 0.4° to the lower left of Venus. This is the closest visible conjunction until 2033.
May 24, 2021: Morning planets Jupiter and Saturn are in the southeast before sunrise. In the evening sky, brilliant Evening Star Venus, Mercury, and Mars line up along the solar system’s plane. The bright moon is in the southeast near Zubenelgenubi, “the southern claw.”
May 23, 2021: Five bright planets parade across the sky. Jupiter and Saturn are visible before sunrise in the southeastern sky. The star Fomalhaut is becoming visible below bright Jupiter and near the horizon. After sundown, Evening Star Venus, Mercury, and Mars are in the western sky. The bright moon is in the southeastern sky during the nighttime hours.
May 22, 2021: Five planets parade across the sky. Jupiter and Saturn are in the southeast before sunrise. Evening Star Venus, Mercury and Mars are in the western sky after sunset. A bright moon is in the southeastern sky.
May 21, 2021: Three bright planets are dancing in the western sky after sundown. Evening Star Venus is entering the sky for a months-long residency after its solar conjunction two months ago. Mercury is heading for a conjunction with Venus after its best evening appearance of the year. Mars continues its eastward march in Gemini, but time is running out on its appearance as it approaches brighter evening twilight and a conjunction with Venus.