April 6, 2021: This morning, the moon, Jupiter, and Saturn are low in the southeast before sunrise. The lunar crescent is 4.7° to the lower right of Saturn, while Jupiter is 12.5° to the lower left of the Ringed Wonder.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:25 a.m. CDT; Sunset, 7:22 p.m. CDT. Check local sources for sunrise and sunset times for your location.
If you are noting the sunrise time and sunset time, the length of daylight is nearing 13 hours. At Chicago’s latitude, this occurs tomorrow and daylight continues to rapidly grow through the month.
This morning the lunar crescent appears near Saturn. The crescent is less than 30% illuminated and appears 4.7° to the lower right of the Ringed Wonder.
A binocular reveals lunar features in high contrast along the terminator, the division between daylight and darkness where the sun is setting on the moon.
Use a binocular to note that Saturn is 2.3° to the upper right of Theta Capricorni (θ Cap on the chart).
Brighter Jupiter – 10° above the southeast horizon – is 12.5° to the lower left of Saturn and 1.9° to the upper left of Deneb Algiedi (δ Cap).
Tomorrow morning, the moon is near Jupiter.
A lunar day lasts the length of a lunar phase cycle, 29.5 days. The moon is in synchronous rotation so that it rotates at the same speed it revolves. The same side of the moon faces our planet. The lunar mountains, craters, and volcanic plains that make the “Man-in-the-Moon” shape are always visible from Earth, except at the New moon phase when the earth-facing side is in full darkness.
We do not see the far side of the moon. That far side receives nearly 15 earth-days of sunlight and darkness. This is the same for the side that faces Earth.
Detailed Note: One hour before sunrise, the moon (24.2d, 29%) is about 10° up in the southeast. Saturn is 4.7° to the upper left of the lunar slice. Bright Jupiter is 12.5° to the lower left of Saturn. In the starfield, Saturn is 2.3° to the upper right of θ Cap. Jupiter is 1.9° to the upper left of Deneb Algiedi. One hour after sunset, Mars (m = 1.4) is over halfway up in the west, 4.8° to the lower left of Elnath
Read more about the planets during April 2021.
April 25, 2021: Mercury passes Evening Star Venus this evening after sunset. Look low in the western sky about 20 minutes after sunset. Mars is marching eastward in Gemini, near the star cluster Messier 35. The bright moon is near Spica.
April 25, 2021: Morning planets Jupiter and Saturn are in the southeast before sunrise. Jupiter is in front of the stars of Aquarius, while Saturn’s starry background is Capricornus.
April 24, 2021: Brilliant Evening Star Venus and bright Mercury are entering the evening sky. They are low in the west-northwest during evening twilight. The bright moon is in the southeast in Virgo. Mars moves into Gemini as it approaches the star cluster Messier 35.
April 24, 2021: The bright gibbous moon is near a star in Virgo during the early morning. From parts of the Western Hemisphere, the moon covers the star. Before sunrise, bright morning planets, Jupiter and Saturn are in the southeast before sunrise.
April 23, 2021: Evening Star Venus and Mercury are entering the evening sky. They are found very low in the west-northwest after sunset. The bright moon is in the southeastern sky during the early evening. Mars is moving toward the star cluster Messier 35.