Stay tuned, stargazers—the year ahead offers many heavenly delights, including a pair of lunar disappearing acts and a potentially surprising comet.
While scores of amazing astronomical phenomena are in the offing, here are our picks for sky-watching events worth circling on your calendar for 2015:
Total Lunar Eclipse, April 4
The new year brings two chances to witness the simplest and most widely shared of sky shows—a total lunar eclipse. First, in the predawn hours of Saturday, April 4, the Earth's dark shadow will blanket the lunar disk as our planet moves between the sun and the moon.
Totality, or total coverage of the moon, begins at 12:00 a.m. GMT (5:00 a.m. PDT). The entire event will be visible from the South Pacific, Alaska, eastern Australia, and Japan. Meanwhile, sky-watchers in North America will witness only a partial, beginning eclipse before sunrise.
Total Lunar Eclipse, September 27
Sky-watchers will have a second chance to witness the moon blush red on the evening of September 27, when another total lunar eclipse will cross the Americas, Europe, and Africa.
The total eclipse begins at 10:07 p.m. EDT, and it will be especially noteworthy as the last of a tetrad of eclipses that began in spring 2014. Since this eclipse will be timed with an especially close supermoon, the effect should be even more dramatic. (Related: "Supermoon Captured: The Best Shots of Biggest Full Moon in 2013.")
Beautiful pairings of planets are always eye-catching. This year there are two duets to watch.
First, on June 30 at dusk, look toward the low western sky for superbright Venus parked next to the largest planet in the solar system, Jupiter.
These two brightest planets in Earth's sky will shine very close together, separated by only 0.3 degrees of distance in the sky. That is close enough to cover the pair with just your pinky finger held at arm's length. As a bonus, 11 days earlier the moon will join the cosmic duo to form a triangle.
Then, on October 23 at dawn, very low in the eastern sky, the most challenging of all naked-eye planets will put on its best performance of the year. Mercury will join a bright trio of planets much higher in the sky—Jupiter, Venus, and Mars forming a cosmic triangle.
On two occasions this year, the moon will huddle with bright planets and stars in the heavens, making for truly eye-catching sky formations. First, on October 8 at dawn, look for the waning crescent moon to join a special gathering of four naked-eye planets in the eastern sky.
Earth's moon will be huddled with Venus, Mars, and Jupiter, with Mercury way below the cosmic trio.
Then the dance of the planets continues on the morning of November 7 as the waning moon comes back for a repeat performance, this time teaming up with Venus and Mars for a pretty conjunction. Sky-watchers should especially note the distinct color contrast between the two inner planets, one white and one red.
If early predictions play out, comet Catalina (C/2013 U10) may brighten enough in December to be seen with binoculars (and possibly even with the naked eye) as it rises higher each day in the early morning skies.
On December 7, the comet should be visible at dawn in the southeastern sky, passing just 5 degrees away from the razor-thin crescent of the brilliant Venus.
If the comet does indeed reach a predicted 4th magnitude or better in brightness, then this triple conjunction should make for an awesome photo opportunity. By New Years Day 2016, Catalina will be passing by one of the brightest stars, Arcturus, only a half degree away. That's a terrific way to round out another wonderful year in stargazing.