Astronomy Events in December 2020

From shooting stars to a rare planetary meet-up, December will be a stargazer’s dream. The long nights will host some of the year’s best astronomical events from a meteor shower to the annual Geminids to a special event on the day of the winter solstice.

This week, four naked eye planets will be visible in the night sky, with Jupiter and Saturn found low in the southwest after sunset and Mars and Venus high in the east. On December 17, the Moon will pass close to the pair of planets, creating a triangle of celestial objects in the sky. Both Jupiter’s Great Red Spot and Saturn’s sensational rings will be easily spotted in telescopes.

The first quarter Moon will appear in the late evening sky and is best viewed from dark locations away from city lights. This is also the peak of the minor meteor shower known as the Ursids. These meteors are produced by dust grains left behind by the periodic comet 8/P Tuttle, which returns every 13 years. At their peak, the Ursids produce about 5-10 meteors per hour.

On the night of December 21, Jupiter and Saturn will make a close approach in the sky, just 0.1 degrees apart. To the naked eye, they will look like a bright double planet, but with binoculars or a telescope, it will be easy to distinguish them. The event will be the closest these two giant planets have been in our view since 1226.

As the year draws to a close, the planets will continue their run-in with each other, bringing the gas giants even closer together. On the night of December 21 (the first sunset of winter for those in the Northern Hemisphere) they will be less than a degree apart, which is very close by astronomical standards. It will be the last time that we will see these two planets so close together until 2080.

The final astronomical event of the month is the lunar eclipse that occurs on the Winter Solstice. This lunar eclipse is not visible from any location on Earth, but some of the effects will be seen. The Moon will enter a shadow zone, called the penumbral region, where it will appear much smaller and darker than it does when it is full. The shadow will slowly move across the surface of the Moon and completely cover it by about 1:30 am local time.

This is the last chance to watch a solar eclipse this year as the planets move back into line with the Sun and the solar eclipse season ends on December 14. Only parts of western North America, Hawaii and the North Pacific Ocean will be able to see the partial eclipse when the Moon passes in front of the disk of the Sun revealing its outer atmosphere, called the Corona. A partial solar eclipse will occur for just a few minutes as the Moon covers a small portion of the Sun.