2023, January 19: Morning Mercury, Thin Moon, Venus Chases Saturn

January 19, 2023:  A razor-thin lunar crescent appears near Mercury before sunrise.  Venus continues to close in on Saturn leading up to their conjunction in three nights.

RECENT PODCASTS

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:14 a.m. CST; Sunset, 4:49 p.m. CST.  Check local sources for sunrise and sunset times for your location.  Times are calculated from the U.S. Naval Observatory’s MICA computer program.

Jupiter’s Great Red Spot’s transit times, when it is in the center of the planet in the southern hemisphere: 5:16 UT, 15:12 UT; Jan. 20, 1:08 UT. Convert the time to your time zone. In the US, subtract five hours for EST, six hours for CST, and so on.  Use a telescope to see the spot.  Times are from Sky & Telescope magazine.

Here is today’s planet forecast:

Morning Sky

Forty-five minutes before sunrise, a razor-thin moon, 8% illuminated, is less than 10° up in the southeast.  Use a binocular to examine the crescent and earthshine on the night portion.  This effect is from sunlight reflected from Earth’s features.

Speedy Mercury is about the same altitude – height above the horizon – as the crescent in the east-southeast, nearly 14° to the moon’s left.  It is the brightest star in this region of the sky and it continues to brighten and rise earlier for the next several mornings. It rises at least 90 minutes before sunup until the 27^th. 

Mercury’s retrograde ended yesterday and it is moving eastward against the starry background.  The planet reaches its largest separation from the sun, known as the greatest elongation, on the 29^th. On this morning, it rises 88 minutes before sunup.

This is the last morning to see the moon during this lunar cycle, known as a lunation.  Cycle 1238 begins at the New moon on the 21^st at 2:53 p.m. CST.

Evening Sky

Forty-five minutes after sundown, brilliant Venus is about 10° above the west-southwest horizon and 3.3° to the lower right of Saturn.  In three nights, the Evening Star passes the Ringed Wonder in a close conjunction. The next easily observed Venus-Saturn conjunction occurs two years from tonight!

Jupiter is about halfway up in the south-southwest, over 40° to the upper left of Venus.  The Jovian Giant is moving slowly eastward in front of Pisces’ dim stars.  This planet moves eastward about half Venus’ speed.  Venus catches Jupiter on March 1^st.  From February 20^th to March 11^th, the two bright planets are within 10° when Venus approaches Jupiter, passes it, and then moves farther eastward from the slower-moving planet.

At this hour, Mars is over halfway up in the east-southeast, to the upper left of Aldebaran, the brightest star in Taurus, and to the right of Capella.  After its retrograde ended a week ago, the planet is slowly marching eastward.

As the sky darkens further and Taurus’ dimmer stars appear, look for Mars’ location compared to the constellation. Use a binocular to spot the Hyades star cluster, the Pleiades cluster, and Zeta Tauri, the Bull’s southern horn.

Turn the binocular toward Venus and Saturn to see them against the starfield in eastern Capricornus. Both planets easily fit into the same field of view.  Venus is 1.3° to the lower right of Nashira.  Saturn is noticeably east of Deneb Algedi and 45 Capricorni (45 Cap on the chart).  The planet is 1.5° to the upper right of Deneb Algedi.

At 7:08 p.m. CST, Jupiter’s Great Red Spot is center stage for sky watchers with telescopes. The planet is over 30° up in the southwest from Chicago.  Sky watchers farther westward see the planet higher in the sky.

At this time Europa is seen against the planet’s clouds. The large satellite moves back against the darkness of the night about the time the spot disappears from view a few minutes before 9:20 p.m. About that time, the moon’s shadow begins to cross the cloud tops.  From Chicago, the shadow is there until the planet sets.  From the Pacific Time Zone, the shadow leaves the planet before 9:30 p.m. PST when Jupiter is less than 10° above the horizon.

RECENT PODCASTS

• 2023, June 30: Venus-Mars Quasi-Conjunction, Moon with Antares
• 2023, June 29: Venus Brakes, Scorpion Moon
• 2023, June 28: Aldebaran Returns, Venus Approaches Mars
• 2023, June 27: Planet Parade, Moon-Spica Conjunction
• 2023, June 26: Spectacular Venus Steps into Leo