Thursday evening December 20the the nearly full 13.5-day waxing gibbous Moon will be within 3o from the reddish star Aldebaran in the constellation Taurus the Bull. Aldebaran is part of the open star cluster the Hyades, a v-shaped asterism making up the face of Taurus.
Comet Wirtanen (69P) has brightened enough to be seen with binoculars and easily captured with a camera. This picture was taken around 6:30 pm CST on December 15th while the skies were hazy with high cirrus clouds and a first quarter Moon over the southern horizon. That combined with light polluted skies of the Kansas City metropolitan area brightened the skies and made the comet not visible with the naked eye but easy to find as it was near the Pleiades open star cluster.
The picture was taken with a Canon Rebel EOS T7i camera with the following settings: 135 mm lens; 13 second exposure time; aperture 5.6; and ISO 32000. The 13 second exposure time was long enough to show short length star trails as the Earth rotated.
This evening, December 16th Comet Wirtanen will still be within a few degrees from the Pleiades again making it fairly easy to locate.
With the Moon waxing from first quarter through full Moon phase and moving past the comet over the next few days means that the comet will not be too visible until the Moon passes by and rises after the comet does. The animated graphic, below, shows the motion of the Moon and the comet between December 15th through December 24th. By the 23rd the comet will be within a few degrees from the bright star Capella in Auriga the Charioteer.
(The animated graphic is set to 1-day intervals.)
In addition to the Moon moving along in its orbit the Earth is also moving eastward along its orbit around the Sun. As the Earth revolves the sky shifts toward the west gradually moving the stars closer to the western horizon. Even the planets gradually shift toward the western horizon and out of sight.
Saturday October 20th is International Observe the Moon Night. That evening the 12-day old waxing gibbous Moon rises around 5 pm local time and will be over the southeast horizon during the evening hours. Joining the Moon are several planets – all located to the west, right, from the Moon. Early, shortly after sunset the inner planet Mercury will be just above the western horizon. Moving east from Mercury is Jupiter, then Saturn, then Mars. The planet Neptune is only a few degrees above the Moon but because of the Moon’s reflected light Neptune will not be visible.
Thursday September 20th the waxing gibbous Moon will be crossing the plane of the ecliptic moving south. This is known as the descending node, one of two intersections the Moon’s orbital path (dark green line) has with the ecliptic.
Our Moon also reaches apogee, (greatest distance from Earth), on Thursday September 20th. At that time the Moon will more or less be at a distance of 31.74 Earth diameters (361,354 km or 224,535 miles) from the Earth.
On the evening of the apogee and node crossing the 11-day old waxing gibbous Moon will be over the southeast horizon at sunset in conjunction with the ‘Red Planet’, passing within 10-11o east from the planet Mars. Joining the Moon and Mars are the planets Saturn, Jupiter, and Venus – all to the west from the Moon and Mars.
Wednesday evening September 19th the 10-day old waxing gibbous Moon will be in conjunction with the outer planet Mars passing within about 3-4o from Mars. Should look good through binoculars.
Look westward for the planets Saturn and Jupiter.
Sunday September 16th the first quarter Moon will be about 8o west from the outer planet Saturn. Then the following evening, Monday the 17th, as the Moon continues orbiting eastward, the waxing gibbous Moon will be within 3-4o from Saturn, but on the east side of Saturn.