As morning twilight is in progress, the moon is high in the southwest among the stars of Leo. It is near the “Sickle of Leo. At the same hour Morning Star Venus is dancing eastward in Libran near Zubenelgenubi. In the evening Mars is in the southeast, marching eastward in Pisces. In the southwest, Jupiter approaches Saturn as a prelude to the Great Conjunction in 15 days.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:03 a.m. CST; Sunset, 4:20 p.m. CST. Check local sources for sunrise and sunset times in your location. Add the time intervals in the notes to your local sunrise or sunset times.
Morning: As morning twilight is in progress, the moon – 21.3 days after the New moon phase and 66% illuminated – is high in the southwest among the stars of Leo. It is near the “Sickle of Leo,” a backwards question mark made by six stars. Because of the moon’s brightness, block the bright moon’s glare with your hand to see the stars. The sickle is a farmer’s tool that has a handle and a curved cutting blade for harvesting crops. In the sky, Regulus is at the bottom of the handle. The star Eta Leonis (η Leo on the chart) – 2.6° to the upper left of the moon this morning – is at the top of the handle. The blade then curves to the left then back to the right.
Farther east, brilliant Venus is stepping through Libra, 3.4° to the lower left of Zubenelgenubi, the Southern Claw. The planet is “that bright star in the east” before sunrise. Notice that Zubeneschamali, the Northern Claw, is nearby. Use a binocular to spot Nu Librae (ν Lib on the chart) 0.6° to the lower left of Venus. Make observations each morning to see Venus’ place change compared to the stars.
Morning detailed note: One hour before sunrise, the bright gibbous moon (21.3d, 66%) – 60° up in the southwest – is 5.9° to the upper right of Regulus and 2.6° to the lower right of Eta Leonis (η Leo, m = 3.5). Farther eastward, Venus is about 12° in altitude above the east-southeast horizon, 3.4° to the lower left of Zubenelgenubi and 0.6° to the upper right of Nu Librae (ν Lib, m = 5.2). Use a binocular to see Venus with the dimmer stars.
Evening: One hour after sunset, bright Mars is in the southeast in front of the dim stars of Pisces. Use a binocular to note that it is inside a triangle made by the stars Epsilon Piscium (ε Psc on the chart), Zeta Piscium (ζ Psc), and 80 Piscium (80 Psc). The Red Planet is to the right of a line that connects ε Psc and ζ Psc.
At this hour the giant planets – Jupiter and Saturn – are in the southwest, less than one-fourth of the way up in the sky. Jupiter is the brightest “star” in this region. Dimmer Saturn is 1.6° to the upper left of the Jovian Giant. Jupiter continues to close in on Saturn as their Great Conjunction is 15 days away.
Read about Mars during December.
Use a binocular to see the starry background. Nightly observations reveal that the planets are moving eastward compared to that background. This evening, Saturn is to the upper left of 56 Sagittarii (56 Sgr on the chart) while Jupiter is 2.8° to the upper left of that star. Saturn is also approaching Sigma Capricorni (σ Cap). Tonight, the separation is 4.0°.
If you’re up late, look for the moon in the east as this day ends. Its gibbous phase is less illuminated than this morning and is now nearly 8° to the lower left of Regulus and the Sickle of Leo. The moon is typically the fastest moving bright object in the solar system. It completes on orbit relative to the stars in 27.3 days and compared to the sun (a cycle of phases) every 29.5 days. Tonight’s moon is 22.0 days after the most recent New moon phase.
Evening detailed note: One hour after sunset, Mars (m = −0.9) is over 40° up in the southeast, moving eastward in Pisces. With a binocular note that it is inside a triangle formed by ε Psc, ζ Psc, and 80 Psc. The Red Planet is 1.1° to the lower left of ε Psc and to the right of a line from ε Psc to ζ Psc. Farther west, Saturn is nearly 19° in altitude above the southwest horizon, 1.6° to the upper left of Jupiter. The Jovian Giant continues to close the gap on the Ring Wonder as the Great Conjunction of December 21 is approaching. Great Conjunction Countdown: 15 days. In the starfield, Saturn is 4.1° to the upper left of 56 Sgr, while Jupiter is 2.8° to the lower left of the star. Saturn is approaching σ Cap. This evening’s gap is 4.0°. As midnight approaches, the moon (22.0d, 58%) is about 12° up in the east, 7.6° to the lower left of Regulus.
Here is more about the planets during December 2020.
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.