April 18, 2021: The crescent moon is high in the west after sunset among the stars of Gemini, below Pollux and Castor. Mars is above the Bull’s horns. Daylight is 13 hours, 30 minutes long.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:05 a.m. CDT; Sunset, 7:35 p.m. CDT. Check local sources for sunrise and sunset times for your location.
The length of daylight has stretched to 13 hours, 30 minutes. Daylight continues to grow 2-3 minutes each day and another 31 minutes by month’s end.
Tomorrow evening, Venus makes its first evening appearance without the aid of a binocular or telescope. It’ll be very low in the west-northwest about 20 minutes after sunset. This evening Venus sets 30 minutes after the sun sets.
An hour after sundown, the moon, 38% illuminated, is nearly two-thirds of the way up in the west, with Gemini as the sidereal background. It is 9.5° to the lower right of Pollux, one of the Twins.
In a binocular, the lunar crescent is 4.8° to the lower right of the star Wasat, “the middle of the sky,” (δ Gem on the chart) and Mebsuta, “the outstretched paw of the lion,” (ε Gem) 4.6° to the lower right of the lunar slice.
The constellations that we recognize today have stars with names that are not associated with the celestial figure. Those star names are associated with constellations of other sky watchers.
In an article printed in 1944, George Davis, Jr. connected the names of the stars with their meanings. Regarding Metsuta, he wrote, “’the outstretched paw of the lion,’ i.e. the lion of the Arabs.”
Mars is to the lower right of the moon, above the horns of Taurus, Elnath and Zeta Tauri (ζ Tau). The Red Planet is 4.3° to the upper right of Zeta Tauri.
In a few days, Mercury begins its best evening appearance of the year. It is at superior conjunction, with the sun between Earth and Mercury, at 8:49 p.m. CDT.
Here’s more about Mars during 2021.
Read about Mars during April.
Detailed Note: One hour before sunrise, Jupiter is nearly 13° in altitude above the east-southeast horizon. It is 3.2° to the upper left of Deneb Algiedi and 0.2° to the lower left of μ Cap. Saturn is 13.9° to the upper right of Jupiter and 1.6° to the upper right of θ Cap. One hour after sunset, the moon (7.0d, 38%) is nearly two-thirds of the way up in the west-southwest, among the stars of Gemini, 9.5° to the lower right of Pollux (β Gem, m = 1.2). Use a binocular to spot Wasat (“the middle of the sky,” δ Gem, m = 3.5) 4.8° to the upper left of the crescent and Mebsuta (‘the outstretched paw of the lion,” ε Gem, m =3.0) 4.6° to the moon’s lower right. Mars – nearly 18° to the moon’s lower right – is above the horns of Taurus, 4.3° to the upper right of ζ Tau. Mercury is at superior conjunction at 8:49 p.m. CDT.
Read more about the planets during April 2021.
October 23, 2021: This morning the bright moon is near the Pleiades star cluster. Mercury is making its best morning appearance. In the evening sky, Venus, Jupiter and Saturn are easy to spot.
October 22. 2021: Speedy Mercury is low in the east before sunrise. It is putting on its best morning performance of the year. Arcturus, in the east-northeast, is about the same altitude as Mercury.
October 21-November 1, 2021: Brilliant Venus steps through Ophiuchus to the upper left of the star Antares in the southwest after sunset . Afterward, the planet steps farther eastward.
October 21, 2021: The bright moon is low in the west about an hour before sunrise. Mercury is in the east at about the same altitude as Arcturus. Venus, Saturn, and Jupiter shine from the evening sky.
December 18, 2021: This is the anticipated launch date of the James Webb Space Telescope, the largest and most sophisticated space telescope view the universe.