What's Up for January? An easy way to spot an elusive outer planet, and a chance to see the quick-moving planet Mercury.
The distant, outer planet Uranus is too faint for most of us to see with the unaided eye, and it can be tough to locate in the sky without a computer-guided telescope. But Uranus can be located now right between the Moon and Mars.
Look for Mercury in the last days of January. You'll need a clear view toward the west, as Mercury will appear just a few degrees above the horizon.
Here are the phases of the Moon for January.
Thursday, Jan. 21, 2021, at 8:11 a.m. EST, the Moon will be at apogee, its farthest from the Earth for this orbit.
By Thursday evening, the Moon will appear to have shifted to about 9 degrees to the other side of the planet Mars, and the pair will continue to separate as the evening progresses.
Saturday evening, Jan. 23, 2021, the planet Mercury will reach its greatest angular separation from the Sun as seen from the Earth for this apparition (called greatest eastern elongation), appearing half-lit through a large enough telescope. Because the angle of the line between the Sun and Mercury and the horizon changes over time, when Mercury and the Sun appear farthest apart as seen from the Earth is not the same as when Mercury appears highest above the horizon in the west-southwest as evening twilight ends. This occurs the next evening.
Saturday at 9:26 p.m. EST, the planet Saturn will pass on the far side of the Sun as seen from the Earth, called conjunction. Saturn will begin emerging from the glow of the dawn on the eastern horizon around Feb. 7, 2021 (depending upon viewing conditions).
Saturday evening into Sunday morning, Jan. 23 to 24, 2021, the bright star Aldebaran will appear below the waxing gibbous Moon. As evening twilight ends (at 6:21 p.m. EST) Aldebaran will appear about 5 degrees below the Moon. The Moon will reach its high point for the night at 8:23 p.m., and Aldebaran will set first in the west-northwest on Sunday morning at 3:28 a.m.
Sunday evening the planet Mercury will appear at its highest above the horizon (5 degrees) at the time evening twilight ends (at 6:22 p.m. EST).
Sometime in the second half of January to early February 2021, a Near-Earth Object (2018 BA3), between 48 to 107 feet (15 and 33 meters) across, will pass the Earth at between 0.7 and 9.2 lunar distances (nominally 1.5), traveling at 18,080 miles per hour (8.08 kilometers per second).
Tuesday evening into Wednesday morning, Jan. 26 to 27, 2021, the bright star Pollux will appear near the waxing gibbous Moon. As evening twilight ends (at 6:24 p.m. EST), Pollux will appear about 9 degrees to the lower left of the Moon. The Moon will reach its high point for the night at 10:59 p.m. with Pollux about 8 degrees to the upper left. By the time morning twilight begins Wednesday morning at 6:18 a.m., Pollux will appear about 6 degrees above the Moon, which will only be about 23 minutes from setting in the west-northwest.
The next full Moon will be on Thursday afternoon, Jan. 28, 2021, appearing opposite the Sun at 2:16 p.m. EST.