The year ahead offers many heavenly delights for sky-watchers, including a pair of lunar eclipses and a comet with potentially surprising brightness.
While scores of amazing astronomical phenomena are in the offing, these eight events are our picks for celestial moments worth circling on your calendar for 2018.
January 31: Super Blue Moon Eclipse
The new year brings two chances to witness one of the most easily accessible sky shows: a total lunar eclipse. The first opportunity arrives on January 31, when Earth's dark shadow will slowly creep over the bright lunar disk as the planet moves between the sun and the moon.
Adding to the excitement, the full moon that night will also be a supermoon, when the lunar orb is relatively close to Earth and so appears bigger and brighter than average. And since the January 31 full moon will be the second one in the month, it will also be what’s known as a blue moon.
Totality, or total coverage of the moon, begins at 7:51 a.m. ET (12:51 UT). The entire eclipse will be visible from the western Pacific Ocean, Alaska, western Canada, Australia, New Zealand, Hawaii, Indonesia, the Philippines, China, and Japan. Sky-watchers in eastern North America will witness only a partial eclipse, since the event starts near sunrise.
March 7-8: Planet Parade
Early risers in late February and into early March will be able to watch a planetary alignment dominate the southeastern sky at dawn, as Saturn, Mars, and Jupiter will seem to hover near each other in the sky. Over a few nights starting on March 7, the waning gibbous moon will appear to pay visits to each planet in the lineup. And on March 8, the moon will tuck itself between Mars and Jupiter.
July 15: Moon Meets Venus
At local sunset, sky-watchers should look for the thin waxing crescent moon to appear in a stunningly close encounter with the planet Venus low in the southwestern sky. North American onlookers will be best positioned to see the two worlds at their closest—they will appear to be separated by less than 1.6 degrees, which is equal to about three lunar disks.
July 27: Total Lunar Eclipse
Sky-watchers will have a second chance for the year to witness the moon go dark on the evening of July 27, when a total lunar eclipse will cross South America, Europe, Australia, Africa, and Asia. This time, the eclipse will occur about half a day after the moon reaches its farthest point from Earth, making this full moon the smallest for 2017. The total eclipse begins at 3:30 p.m. ET (19:30 UT). During this event, the moon will travel through the darkest part of Earth’s shadow, potentially making this a particularly deep total eclipse.
July 27: Mars at Its Best
On the same date as the total lunar eclipse, Mars will seem to glide close to the moon just as it reaches its peak visibility for the year. The red planet will be at opposition, when it sits opposite to the sun in the sky, from our perspective. During opposition, Mars will look like a super-bright orange star in the southern sky.
Mars does not have a perfectly circular orbit around the sun, so the red planet gets nearer and farther from Earth over time. This year, Mars will be especially close to Earth shortly after opposition, coming within 35.8 million miles of us on July 31. This combination means that Mars will be at its biggest and brightest since 2003, and it won’t get this close to us again until 2035.
While the planet will look spectacular to the naked eye, people using backyard telescopes will have exceptional views of various Martian surface features, such as its white polar caps and dark volcanic plains.
August 11: Partial Solar Eclipse
At sunrise on August 11, a partial solar eclipse will greet sky-watchers across the high northern regions of North America and Europe, as well as Greenland, Iceland, and Asia. How big a solar bite you’ll see depends on your location. The most spectacular views from land will be from remote sites in Russia and large portions of northeastern China, such as around the city of Harbin, where the moon will cover 37 percent of the sun a few minutes before local sunset.
August 12-13: Perseid Meteor Shower
Considered one of the most intense annual meteor showers, the Perseids regularly produce up to 60 shooting stars an hour at their peak. This year promises to be particularly good in terms of performance, since the peak will coincide with a dark, moonless sky on the night of August 12 and into the predawn hours of August 13. The thin crescent moon will set during the early evening, creating excellent viewing conditions across the Northern Hemisphere.
December 12: Comet Encounter
If early predictions play out, comet 46P/ Wirtanen may brighten enough in December to be spotted easily with the unaided eye. If it does attain naked-eye visibility, it will be the brightest comet seen from the Northern Hemisphere in more than five years. The icy interloper will reach perihelion—its closest approach to the sun—on December 12 and will be traveling through the bright winter constellation Taurus, the bull.
Only four days after it slingshots around the sun, the comet will make its closest approach to Earth, coming within 7.2 million miles of the planet on its way toward the outer solar system. At this point, the comet should be easy to hunt down as it passes by the brilliant Pleiades and Hyades star clusters.
That's a terrific way to round out another wonderful year in stargazing. Happy hunting!