Tonight is the longest night of the year. You can use it to see a meteor shower and the historic Jupiter-Saturn 'double planet.'
- Monday brings the longest night of the year, along with the opportunity to watch a rare celestial occurrence.
- Jupiter and Saturn will appear so near each another in the sky that they seem to touch. Their conjunction hasn't come this close since 1226.
- At the same time, the Ursids meteor shower will send shooting stars streaking across the night sky.
Monday night brings an astronomical anomaly. It's the longest night of the year for the Northern Hemisphere - the winter solstice - and it will feature both a meteor shower and a once-in-800-years "double planet."
You don't need a telescope to see any of this.
Jupiter and Saturn, which shine as bright as stars in the night sky, will appear so close to each other that they seem to touch. An alignment, or conjunction, between these two planets happens every 20 years, but the last time they looked this close from Earth's vantage point was on March 4, 1226.
At the same time, the Ursids meteor shower will be peaking, sending five to 10 shooting stars across the night sky per hour. That's because Earth will be passing through the thickest part of a trail of debris left behind by comet 8P/Tuttle. As those bits of ice and dust burn up in the atmosphere, they can leave bright flares in the sky.
This will all take place on the winter solstice, when the tilt of Earth's axis and the shape of its orbit bring the Northern Hemisphere to its farthest point from the sun. That makes Monday the shortest day (and longest night) of the year for that half of the globe.
You can take advantage of the long night to see the historic double planet and bonus meteor shower.
How to see Jupiter and Saturn meet amid shooting stars
Jupiter and Saturn are separated by more than four times the distance between Earth and the sun. But on Monday night, they will be separated in the sky by a distance equal to about one-fifth of a full moon's diameter. According to NASA, a pinkie finger at arm's length should easily cover both Jupiter and Saturn in the sky.
This "Christmas star," as the conjunction has been nicknamed, should appear brighter than nearly every star in the sky, according to NASA.
So you should be able to see it with the naked eye, especially if you're far from city lights. A telescope or binoculars could help you spy the planets' moons. Your phone's camera could even capture photos of the merging planets, according to NASA - if your timing is right.
"You will need to have a clear southwestern horizon and no low clouds in the distance," Patrick Hartigan, a professor of physics and astronomy at Rice University, said on his website.
For viewers in the US, Canada, and Europe, it could be challenging to see the conjunction because of how low it will be on the horizon, Hartigan said.
"Viewing conditions are best close to the equator, though no matter where you are, there is maybe an hour or so to observe this conjunction before the planets sink into the haze," he added.
For best viewing of the conjunction, head out around twilight - the hour after sunset - and point your telescope toward the southwestern sky. (Websites like Stellarium can help you orient your telescope.)
To catch the shooting stars, stay out a bit later. Once the moon sets - after midnight - dark skies will make a better backdrop to spot meteors.
If it ends up cloudy on Monday, don't worry. The conjunction will last through December 25. The solstice is just when the two planets will be at their very closest in the sky.
The Lowell Observatory in Flagstaff, Arizona, will host a YouTube livestream of views through its telescopes starting at 7 p.m. ET on Monday. In Rome, the Virtual Telescope Project also plans to share live views of the conjunction.
Aylin Woodward contributed reporting.