Sky Tour Podcast for February 2023
This month’s episode is sponsored by Celestron, manufacturer of high-quality telescopes and an industry leader in developing exciting optical products with revolutionary technologies.
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I’m Kelly Beatty of Sky & Telescope magazine, and tonight we’re going on a tour of the stars and planets that you’ll see overhead during February. Here’s this month’s to-do list: we’ll explore the Moon’s phases, watch three planets evening sky, take stock of winter’s brightest stars, and track down two lesser-known constellations. So grab your curiosity, and come along on this month’s Sky Tour.
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Last month I mentioned how Earth is actually its closest to the Sun during early January. I know, I know — the cold weather here in the Northern Hemisphere is telling a very different story. But, because we’re closer than average to the Sun right now, Earth is moving along its orbit at a faster clip too, and that means we northerners are rapidly moving away from the depth of winter — at least astronomically speaking. In fact, February 4th marks the midway point between December’s solstice and the March equinox. So daytimes are getting longer and nights shorter. 
Did you know that you can tell the season just by looking at the Moon? It’s true. You’ve probably noticed that the Sun stays pretty low in the sky even at midday during winter, but that it gets very high up during the summer. But for the Moon, it’s just the opposite. The full Moon climbs its highest in the sky during winter months. February starts out with the Moon big, fat, and very high in the evening sky. The full Snow Moon falls on the 5th, followed by last quarter on the 13th, and new Moon on the 20th. Soon after that it appears in the southwest after sunset, first as a thin crescent, then reaching first quarter on the 27th. 
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We’ve had a terrific run of evening planets for most of the past year, with Jupiter, Saturn, and Mars leading the way. But all that is changing as we move into February. Saturn has disappeared from view, and yet Venus has emerged from the twilight glow in the west as if to replace it. 
So turn your gaze westward maybe 30 to 45 minutes after sunset, and in the dwindling twilight you’ll easily pick out dazzling Venus low down and Jupiter, somewhat dimmer, to its upper left. At the beginning of February these two beacons are separated by about three times the width of your clench fist held at arm’s length. But as the days go by, they slide closer together, with Venus inching upward and Jupiter downward. Meanwhile, far to their upper left, nearly overhead, is Mars, the Red Planet. It’s no competition for Venus and Jupiter, but it’s still quite bright and easy to spot.
OK, head to your calendar, whether digital or old-school printed paper, and circle the evening of February 22nd. By then the two planets will be less than one fist apart — but a razor-thin crescent Moon will have joined the planet party, parked just to Jupiter’s lower left. How pretty will that be?
And as the sky darkens, keep an eye on the Moon for a faint, ghostly glow filling in the shadowed part of its disk. This is called Earthshine. It’s the ricochet of sunlight that first reflects off our planet, and then onto the Moon’s night hemisphere, lighting up the lunar landscape brightly enough that we can see it back here on Earth. Another way to think of it is to imagine that you’re standing on the Moon. From here the we see the sunlit part of the Moon as just a thin crescent. But from your lunar landing site, Earth would appear almost full. Now, Earth is about four times the Moon’s diameter, and all our clouds and snow make us more reflective overall. So a full Earth, as seen from the Moon, is 100 times brighter than the full Moons we see from here. Wow! That’s a planet-size floodlight shining onto the lunar night.
Now, for most of us across North America, Europe, and most of Asia, February nights are too cold to comfortably spend much time outdoors. So this month, let’s try a stargazing activity that I promise you can finish in 5 minutes or less. Ready? Let’s go.
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Some clear evening in February, go outside after it’s gotten reasonably dark, around 7 pm, then find a spot with a wide view all around, and face south. If you’re not sure of that direction, note where the Sun sets and then just make a quarter turn to your left. Give your eyes a couple of minutes to adjust to the darkness, and then look high up to spot Mars. 
Now sweep your eyes to the right, and make a mental snapshot of what you see. Apart from Jupiter and Venus, you’re not seeing many obvious stars, are you? Well, you can probably pick out the Great Square of Pegasus, a giant diamond of four medium-bright stars over the western horizon. It’s a little larger than the size of your clenched fist. But nothing really commands your attention, right? 
Now go back to Mars and sweep your gaze to the left half of the sky, toward east, and to the area below Mars. What a difference! Even if you have a lot of light pollution, you’ll see a bunch of bright stars. And why is that? Well, it’s not obvious, but in that direction you’re looking outward along the plane of our home galaxy, Milky Way. And it happens that many bright stars are relatively close by on that side of the Milky Way’s disk. The most obvious one, the lowest of the lot down in the southeast, is Sirius. It’s actually the brightest star in the entire nighttime sky and only 8½ light years from Earth.
Let’s work our way upward from Sirius. To its upper right is Orion, the Hunter, arguably the brightest and most striking constellation in the northern sky. Orion is easily distinguished even through light pollution because of the row of three medium-bright stars that form his belt. To the belt’s upper left is the bright red supergiant star Betelgeuse, and to its lower right is icy-white Rigel; these two stars mark his shoulder and knee, respectively. 
OK, our 5 minutes are up. Are you game to stay out a little longer? Give me just another few minutes, OK?
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Being a hunter, Orion needs hunting dogs. Brilliant Sirius is the anchor star in Canis Major, the Big Dog. In fact, Sirius is often called the Dog Star. Woof! Higher up, directly to Orion’s left, is Procyon, in Canis Minor, the Little Dog. arf! These two constellations faithfully follow the hunter across the sky throughout the night, ready to snatch up his prey.
Let’s broaden out the view. Follow Orion’s belt to the upper right for about two fists, and you’ll see a bright, slightly reddish star called Aldebaran, marking the angry eye of Taurus, the Bull. Classified as an orange giant star, Aldebaran is more than 40 times the Sun’s diameter. It’s a relatively close 65 light-years away. In other words, the light you’re seeing now left Aldebaran in 1958 — the same year that the U.S. launched its first artificial satellite, Explorer 1. And Aldebaran is on the left edge of a loose cluster of stars called the Hyades. But Aldebaran isn’t part of this cluster; it’s just closer to us along the same line of sight.
Let your eyes drift a little higher to the upper right, not quite two fists from Mars, and look for a small cluster of stars called the Pleiades or sometimes the Seven Sisters. Look carefully and you might see six or seven, but there are actually hundreds of stars here. They all formed together about 100 million years ago, when dinosaurs were in their prime. The entire cluster is about twice the size of the full Moon, and it looks terrific through binoculars or a small telescope. The Pleiades have actually been a little controversial recently, because astronomers couldn’t agree on how far away they are. But now the debate is over: The true distance is about 450 light-years.
Now let’s gaze farther upward, almost directly overhead. There we find the bright Capella, anchor star in the constellation Auriga [are-REE-guh], a charioteer who moonlights as a goatherder. From there, let your gaze settle back down toward the horizon, and you’ll pass the Twins of Gemini, Castor and slightly brighter Pollux. All the stars mentioned so far are landmarks in the late autumn and winter sky.
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I don’t want to overstay my welcome, but if you can stay for just a few more minutes, we can go on a kind of treasure hunt for two lesser-known constellations. You should do this around the middle of February, when the Moon isn’t up and the sky is as dark as possible. Finding a place that doesn’t have many strong lights nearby will help too.
Our first target is a celestial rabbit, named Lepus. Our little hare is hiding in plain sight, right underneath Orion and just to the right of Sirius. If your sky is good and dark, you can make out a pair of ears sticking up toward Rigel, and the hare’s body and tail bend toward upper left. 
Now for our second faint target. Betelgeuse, Sirius, and Procyon form a beautiful equilateral triangle in the sky, known to stargazers as the Winter Triangle. There’s nothing much inside that triangle, as bright stars go, but this is the realm of the constellation Monoceros. Can you guess what it represents? You probably know that “mono” means one or single, and “ceros” derives from the ancient Greek word for horn. Now, what has just one horn? Hmm… well, it could be a rhino, but that’s not a very mythical. Aha! Monoceros is the celestial unicorn. This dimly drawn beast is facing Orion. Think of Procyon and the little dog as riding on its back.
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Now that you’ve been outside for a while, I’ve got one question for you. How many stars can you see? Well, on a moonless night far from any light pollution, your eyes can pick out a couple of thousand stars. So really my question is: How faint are the faintest stars that you can see? This isn’t a random question. Just last month, a team of scientists announced that the skyglow from light pollution is increasing 10% per year. And how did they determine this sad fact, By tapping into a worldwide database of sky-darkness measurements made by everyday folks like you and me. This is important work, and yet it’s very easy to participate. This month the target area is Orion. Easy, right? No experience or equipment is needed — all you need are your eyes, a moonless night, and a willingness to help. So, please, please go to the website globe at night dot org to find out what you need to do.

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Thanks for letting me show you around the stars and planets for another month. If you want more tips for viewing the night sky, including a free, interactive star chart for any time or date, check out our website, SkyandTelescope.org.
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And if you want to explore the solar system and universe more deeply, check out the full line of binoculars and telescopes available at Celestron.com.
Sky Tour is a production of Sky & Telescope, a division of the American Astronomical Society, and is produced by me, Kelly Beatty.
Next month we’ll explore why Sirius is as famous in summer as it is in winter. Until then, I wish you Clear Skies.