Located in the constellation Cancer, the Beehive Cluster is composed of about 1000 stars. Two gas-giant planets in the cluster are highlighted above. Image Credit: Stuart Heggie via NASA
You’re going to need a pair of binoculars. Around 11:59 p.m. EST, look east. You’ll see a giant disc in the sky marked with mysterious shadows that appear to be dark oceans. That is the Moon. Look a little to the left, and a little bit down, and for the first time in your life, you’ll probably see the constellation Cancer. Now we’re getting somewhere.
Cancer is the ninja of constellations. It’s hard to find, but when the skies are dark and clear and you manage to spot it, lots of things happen very quickly: First, you pat yourself on the back, because it is comprised only of a few faint stars, including one called Arkushanangarushashutu, which is Babylonian for “southeast star in the Crab.” Second, you wonder how the ancients got a crab out of that (it looks a lot more like a wishbone or Y). Third, you notice what appears to be a vague haze or cloud within its little crab body.
That’s what we’re after tonight! Within the crab is not a smear, but rather, a grouping of a thousand stars. (You won’t see that many.) This is the Beehive Cluster, also called Praesepe. It is an “open cluster”—that is, a collection of stars formed from the same stellar nursery. (Praesepe is Latin for “manger.”) Some of the stars in the Beehive are Sun-like with Jupiter-like gas giants orbiting them. You can see two of these planets, Pr0201b and Pr 0211b, highlighted in the top image—they are, NASA says, "the first b's in the Beehive." (You definitely won’t see planets tonight.)
Who first put the beehive on the map? The father of modern science himself, Galileo, who spied it with his paper telescope. That’s why you need binoculars tonight: Because unless you were born on Krypton, you cannot resolve these stars with the naked eye. That you need only a decent set of binoculars makes this a perfect celestial starter kit. You can enjoy the experience without figuring out how to aim and focus a telescope in the freezing night air (or, thanks to climate change, in the sweltering, mosquito-dense night air).
So what can you expect? Galileo saw 40 stars in the cluster. Forty might not seem all that special, but it’s an awful lot for such a small space, and if you can see even a quarter of that, you’ll be glad you took the time. The cluster’s stars—some small and dim, some larger and less dim—come together to form the appearance of an electric, 3D image of swarming bees. (They won’t be moving, though, and if they are, run.)
The usual terms and conditions apply. You will need to be in an area of very little light pollution. Cancer is really hard to see, and if you’re competing against the floodlights of a Walmart parking lot, you may as well save yourself the trouble and call it an early night. While the position of the waning gibbous Moon will help you locate the beehive, the light reflecting off it won’t, but we have to play the hand we’re dealt. Here’s the good news: Your binoculars are likely similar in power to Galileo’s telescope. They might even be better. So get out there and give it a try. If you can find the Moon, you can find a star cluster. And if you can’t, the Moon is reason enough to look up tonight. You really can’t lose.