Sunday, November 22
While a half-illuminated Moon floats in Aquarius, turn your gaze south late this evening to find another watery constellation: Eridanus the River. This southern constellation never fully breaches the horizon for many Northern Hemisphere observers, but is highest tonight at roughly 10:30 P.M. local time. One of the largest constellations in the sky, Eridanus winds its way from near Orion and Lepus down past Fornax and below the equator to end near Horologium and Phoenix.
One of the most famous deep-sky objects hiding in this constellation is IC 2118, also called the Witch Head Nebula. This faint reflection nebula sits less than 3° west of Rigel in Orion; the two are associated in three-dimensional space as well, as reflected light from this bright star causes the nebula’s glow. This faint cloud of interstellar dust is difficult to see even through a telescope, but astroimagers can bring out its subtle detail with longer exposures. If you want to test your photo processing skills or observing site’s dark-sky conditions, this is the target for you.
Sunrise: 6:54 A.M.
Sunset: 4:38 P.M.
Moonrise: 1:24 P.M.
Moonset: —
Moon Phase: Waxing gibbous (56%)
Monday, November 23
The Moon passes 5° south of Neptune at 7 A.M. EST, but both are below the horizon at the time. Instead, you can catch the pair after sunset, when they are just over 6° apart in the constellation Aquarius.
Neptune, whose dim magnitude 8 glow will require binoculars or a small scope, presents a bluish disk just 2" across. It currently sits less than 1° east of magnitude 4.2 Phi (φ) Aquarii. Neptune is now roughly 30 astronomical units from Earth, where 1 astronomical unit, or AU, is the average Earth-Sun distance. That means its light takes a little over four hours to reach us here on Earth. Neptune has been slowly sliding southwest against the background stars, but in just a few days it will reach its stationary point and about-face to begin tracking northeast.
Sunrise: 6:55 A.M.
Sunset: 4:38 P.M.
Moonrise: 1:50 P.M.
Moonset: 12:17 A.M.
Moon Phase: Waxing gibbous (65%)
Tuesday, November 24
Starting an hour before sunrise, both Mercury and Venus should be easy to spot in the brightening sky. Mercury, just rising among the stars of Libra, is an easy magnitude –0.7. Venus is impossible to miss at magnitude –4. It’s sitting less than 2° from magnitude 4 Kappa (κ) Virginis and is now 10° due east of bright Spica.
Through a telescope, Mercury appears 90 percent illuminated and 5" across. It is just 0.5° from Nu (ν) Librae, whose dim, magnitude 5 glow will fade quickly as dawn approaches. Venus is a much larger 12" across, with a disk that’s 87 percent lit.
See how long you can follow the planets into the morning sky, but take care — stop using any optical equipment, including binoculars, at least several minutes before sunrise to avoid accidentally damaging your eyes.
Sunrise: 6:56 A.M.
Sunset: 4:37 P.M.
Moonrise: 2:13 P.M.
Moonset: 1:17 A.M.
Moon Phase: Waxing gibbous (74%)
Wednesday, November 25
The Moon passes 5° south of Mars at 3 P.M. EST. By sunset, our satellite is just 5.2° from the Red Planet. Mars remains in Pisces the Fish, while the Moon is south-southwest of the planet, just over the border in Cetus the Whale.
Let full darkness fall, then swing your scope to Mars to observe its 15"-wide disk, which shines at magnitude –1.3. Around 8 P.M. EST, the bright spot of Olympus Mons is visible on the disk; it will rotate out of view over the next two hours or so. The dark swaths of first Mare Sirenum, and later Mare Cimmerium, are also visible south of Olympus Mons.
NASA’s Mars 2020 mission is now less than 100 days from its landing on Mars. Recently, mission scientists released audio recorded by the Perseverance rover’s microphones as it travels through deep space. The sound is generated by mechanical vibrations that the microphone’s equipment has turned into an electrical signal. The soft buzz comes from the rover’s heat rejection fluid pump, which maintains the equipment’s temperature even in frigid cold.
Sunrise: 6:57 A.M.
Sunset: 4:37 P.M.
Moonrise: 2:36 P.M.
Moonset: 2:15 A.M.
Moon Phase: Waxing gibbous (82%)