The moon will be dancing with multiple planetary partners this month, offering delights in both the morning and evening skies. And as the nights get warmer for viewers in the Northern Hemisphere, sky-watchers lingering outside will be in for a spring treat: a lovely meteor shower streaking across the constellation Lyra.
So dust off those binoculars, and mark your April calendar!
Mars passes the Pleiades—April 1
A beautiful pairing of orange-hued Mars and the Pleiades star cluster will greet viewers as soon as darkness falls on the first of the month. Both objects will dominate the western sky and will be separated by only three degrees, a gap that can be covered by your three middle fingers held at arm’s length.
If you can, definitely check out the Pleiades with binoculars or a backyard telescope. This cluster, also known as the Seven Sisters, is one of the closest to Earth at some 300 light-years away. Although it contains more than a thousand confirmed members, it gets its nickname from the seven stars that can be easily spotted with the unaided eye, even today under brightly lit city skies.
Moon meets Venus—April 2
Early risers on the second will be treated to the bright, star-like planet Venus snuggling close to the waning crescent moon. The pair will be hanging in the southeastern sky about an hour before local sunrise.
Pallas at opposition—April 9
One of the largest known asteroids, 2 Pallas, will be at its brightest in our evening skies on the 9th, and will be easy to find as it glides past one of the brightest stars in the northern spring sky. Located some 147 million miles from Earth, the giant celestial rock will be officially at opposition, when it is opposite in the sky from the sun, as seen from Earth. Roughly 326 miles wide, Pallas will be a binocular target even from light-polluted city suburbs for the next couple of weeks.
Pallas is currently sailing through the bright constellation Boötes, the herdsman, located in the southeastern evening sky. It is visible very close to the bright orange star Arcturus; their apparent separation in the sky is about equal to the width of your fist held at arm’s length.
That makes the bright star a convenient guidepost for hunting down the asteroid. Start by using binoculars to home in on Arcturus around local midnight, when the constellation will reach its highest point in the sky. Because many of the points of light in this field of view can look the same, the best way to identify an asteroid is by its telltale motion. Sketch the position of about a dozen of the stars you see. In about half an hour, observe the same star field once more and make the same sketch. The one “star” that has moved will be Pallas.
Battle of the red orbs—April 11
Evening sky-watchers will be seeing red on the 11th, as two of the brightest and reddest celestial objects huddle in the same part of the sky. Gaze toward the west after darkness falls to see ruddy Mars approaching the much brighter red star Aldebaran, also known as the eye of Taurus, the bull. The celestial duo will sit about seven degrees apart, a gap that is a bit more than the width of your fist held at arm’s length.
While they seem comparable in our skies as points of light, Mars is a third the size of Earth and is less than 190 million miles away. Meanwhile, Aldebaran is a red giant star many times larger than our sun that is located 65 light-years distant.
Lyrid meteors peak—April 22
In the predawn hours of the 22nd, the Lyrid meteor shower will reach its peak. Under ideal, dark skies, we can expect to see anywhere between 15 to 20 shooting stars an hour during this annual shower. This year, however, sky-watchers will have to contend with a waning gibbous moon—only three days past the full phase—rising just before local midnight. This means the lunar glare will wash out the fainter shooting stars around dawn, and the best views might be relegated to the darker late nights of the 21st and 22nd.
Individual shooting stars will appear to stream from the shower's namesake constellation Lyra. Meteors will seem to radiate from the area of sky occupied by the brilliant star Vega, which currently shines nearly overhead just before dawn.
The Lyrids are known to have surprise outbursts, such as one in 1982 that saw as many as 250 meteors appear in a single hour. And the 1922 performance above Europe is the stuff of legends, with records of around 500 shooting stars an hour. These spectacles can’t be predicted, so the only way to know for sure if one is happening is to go out and look up.
Moon joins Jupiter—April 23
On the 23rd, early risers will see the waning gibbous moon make a very close approach to the brilliant planet Jupiter. The pair will appear to be less than two degrees apart, meaning you could cover the cosmic duo with a just two fingers held at arm’s length. This celestial encounter will offer a great photo opportunity, with the pair hanging low in the southwestern sky about 45 minutes before local sunrise.
Moon skirts Saturn—April 25
Only a couple of mornings after Jupiter’s brush with our moon, magnificent Saturn will get its turn to hang out with Earth’s companion in our skies. Look for the brilliant moon to position itself less than half a degree from the star-like ringed world at dawn in the high southern sky. If you can, don’t forget to train your telescope on Saturn and spy those famous rings that encircle the gas giant.