The longest night of the entire year will feature an astronomical double-header giving stargazers plenty to look for from sundown until daybreak.
The December solstice occurs on Monday at 5:02 a.m. EST, the day when the sun’s rays are most direct over the Southern Hemisphere.
For the Northern Hemisphere, this is the shortest day and longest night of the year and marks the transition from astronomical autumn to astronomical winter. Meanwhile, this solstice signals the start of astronomical summer south of the equator with Dec. 21 bringing the longest day and shortest night of the year.
For folks across the Northern Hemisphere, the extended hours of darkness will feature two celestial happenings that may be worth staying up late to see.
The first of the two events can be seen globally and is an extraordinarily close encounter between the two largest planets in the solar system. However, it will only be visible for an hour or two after sunset in the western sky on Dec. 21.
Jupiter and Saturn will be so close to each other that they will look more like one single object in the sky, leading some to nickname the event the ‘Christmas Star’ due to its proximity to the holiday season.
Later in the night, shooting stars will streak across the sky as the first of winter’s two meteor showers reaches its peak.
The Ursid meteor shower will unfold during the second half of Monday night and into the early hours of Tuesday morning, but will only be visible for skywatchers across the Northern Hemisphere.
“The Ursids are often neglected due to the fact it peaks just before Christmas and the rates are much less than the Geminds, which peaks just a week before the Ursids,” the American Meteor Society explained.
“Observers will normally see 5-10 Ursids per hour during the late morning hours on the date of maximum activity,” the AMS added. “There have been occasional outbursts when rates have exceeded 25 per hour.”
Generally good weather is in the offing for much of the United States for both events with cloud-free conditions in the forecast from California to Colorado and through the Carolinas. However, some patchy clouds could linger along the Gulf Coast and over Southern California.
Those across the northern tier of the U.S. and over much of Canada looking forward to these events may not be as lucky with cloudy conditions expected to obscure the sky throughout much of Monday night. The best chances for breaks in the clouds will be over Atlantic Canada and in the interior Pacific Northwest into the northern Plains.
After the Ursids subside, there will be one more opportunity to view a meteor shower in the coming weeks before there is a three-month spell of no major meteor showers.
On the second night of January, the Quadrantid meteor shower will peak, and like the Ursids, will only be visible across the Northern Hemisphere. This shower tends to be more impressive than its predecessor and can feature anywhere from 20 to 120 meteors per hour, according to the AMS.
Once the Quadrantids come and go, it will be three long months before another meteor shower sparkles in the night sky – the Lyrids in late April.