Don't Miss the December Night Sky
Space is the stage for the final interstellar show of 2020.
Planets, meteors, and constellations are the stars this month. The light shows in our neighborhoods should just be the appetizer to what's going on in our night sky. We've all heard that the "Christmas Star" will reveal itself on December 21 (details below), but you don't have to wait until then to start looking up. Karl Brehm, our resident astronomer, filled us in on the dates and details to take note of as we scout the sky this month.
December 12 & 13: Venus and the Moon come Together The Moon and the brightest planet in Earth's sky, Venus, will come together on the morning of December 12. The two will have a conjunction later that day, but the closest you'll be able to see them will be early in the morning after Venus rises around 5:11 am. That will give you a little more than two hours to catch them before the sun rises. The duo will still be close together on the morning of December 13, when Venus will rise just a couple of minutes later.
Germinid Meteor Shower
December 13: The Geminid Meteor Shower Peaks One of the year's best meteor showers will hit its peak the night of December 13 into the morning of December 14. The shower runs annually from December 7-17. The Geminids are almost always a good show, despite arriving during a frigid month. This year, you might see as many as 100 – 120 “multicolored” meteors per hour. Plus, the Geminids can produce fireballs, which are particularly bright, showstopping meteors. The best viewing comes around 2-3 am. The shower, comprised of debris coming from Asteroid 3200 Phaethon, which was discovered in 1982. The Geminids are named after Gemini, as they appear to originate from the constellation. And this year, the shower will be visible a day before a new moon, meaning skies will be especially dark!
December 14: New Moon The Moon will be located on the same side of the Earth as the Sun and will not be visible in the night sky. This phase occurs at 9:16 am MST. This is the best time of the month to observe faint objects such as galaxies and star clusters because there is no moonlight to interfere. December 16 & 17: Jupiter, Saturn, and the Moon have a Close Encounter Just days before the great conjunction, we'll have a run of conjunctions between Jupiter and the moon as well as Saturn and the moon. With the gas giants setting early in the evening, the moment of their closest approach to the moon won't be visible from the US. However, early in the evening of both December 16 and 17, the moon will be close to the big planets, creating a small triangle of celestial objects. Both Jupiter and Saturn rise while the sun is still up and aren't visible until the sun has sufficiently faded from view. They'll remain visible low in the sky until just after 7 pm. December 21: December Solstice The December Solstice occurs at 3:02 am MST. The South Pole of the earth will be tilted toward the Sun, which will have reached its southernmost position in the sky and will be directly over the Tropic of Capricorn at 23.44 degrees south latitude. This is the first day of winter (winter solstice) in the Northern Hemisphere and the first day of summer (summer solstice) in the Southern Hemisphere.
The Great Conjunction
December 21: The Great Conjunction between Saturn and Jupiter Jupiter and Saturn are going to have a very close approach on December 21. It's going to be their closest approach—from our perspective on Earth—since 1623. You won't be able to spot them this close again until 2080. That makes this a genuinely once-in-a-lifetime opportunity. You'll even be able to spot the two gas giants in the same field of view through a telescope. A conjunction between the two is referred to as a “great conjunction” because it's the rarest of all two-planet conjunctions that are visible with the naked eye. (Also, some are referring to this as the "Christmas star.") This means the two will shine brightly as a "double planet," appearing just a tenth of a degree apart —or about the thickness of a dime at arm's length. Look in the South-Southwest sky at sunset or just after. They'll only be above the horizon for a little while with a setting time just before 7 pm. December 22: Ursid Meteor Shower Hits its Peak The Ursids—sometimes called the "cursed Ursids"—will look pretty lame in comparison to the Geminids earlier in the month. The shower is expected to produce about 10 meteors per hour. The Ursids are a minor meteor shower produced by dust grains left behind by comet Tuttle, which was first discovered in 1790. The shower runs annually from December 17-25. It peaks this year on the night of the 21st and morning of the 22nd. The first quarter moon should set just after midnight leaving dark skies for what could be a good show. The best viewing will be just after midnight until 2 am from a dark location far away from city lights. Meteors will radiate from the constellation Ursa Minor, but can appear anywhere in the sky.
December 30: Full Moon The Moon will be located on the opposite side of the Earth as the Sun and its face will be fully illuminated. This phase occurs at 8:28 pm MST. This full moon was known by early Native American tribes as the Cold Moon because this is the time of year when the cold winter air settles in and the nights become long and dark. This moon has also been known as the Long Nights Moon and the Moon Before Yule.
Karl is the Aquatics Facility Coordinator at the HRCA's Northridge Recreation Center. His interest in astronomy took off at age six when Karl asked his dad to let him watch a total lunar eclipse. He majored in Recreation Management at the University of Kansas with a minor in Astronomy. Karl has always been interested in space and astronomy and would consider it his number one hobby. He has worked at HRCA since 2006 and can often be found helping at the Backcountry Wilderness Area's astronomy programs at Base Camp.