Hey, sky fans. With all this talk about the fun happening with the planets in the mornings, let’s not forget that there are things to look at in the night, too. If you can make it outside these days, figure mid-evening, you’ll see one of the most famous and recognizable constellations of them all, Orion the Hunter, in perfect position, standing tall over the southern skies, protecting the world from the running of the bulls. The Tauri. Tauruses? Taur…bulls. We’ll leave it at bulls.
If you need help finding Orion, look for the nearly straight line of three almost equally spaced stars that form his belt: Alnitak; Alnilam, and Mintaka. Then, if you picture him with his back to you, you can imagine the giant bright orange star Betelgeuse is his left shoulder, and the bright, icy blue-white supergiant Rigel is his right leg. That sounds like a radio commercial. Try new Icy-Blue Rigel; the most delicious gum there is.
Here’s a screenshot from Stellarium of the southern skies where I live at around 8:30 tonight. Orion is right in the middle with Sirius (in Canis Major) to the lower left and Aldebaran (in Tuarus) in the upper right, as well as a couple of other stars.
Betelgeuse is one of the most famous stars in the sky, maybe the most famous after Polaris, the north star. Sitting there, glowing orange, ringed by the Winter Circle, it’s a sight that always stops me in my tracks, even on the most frigid of winter nights.
Like most things astronomical, it’s really far away. In this case, it’s so far that its light has taken about 600 years to reach us here on Earth. That’s 3.6 quadrillion miles (3,600,000,000,000,000) at 6 trillion miles to the light year! That’s so far it doesn’t even matter how far it is. It’s a long, loooooong way off. Much too far for us to ever visit. Even if we were able to get there, though, Betelgeuse might not be there when we did! Sooner or later, all stars run out of fuel, and die. The sun will one day. When Betelgeuse does, it’ll explode and go out as a supernova, which is one of the most violent things the universe can muster. That’s expected to happen some time in the next million years or so. So, we’ll probably miss it. There is that chance, though, that it might have already happened, and we won’t know it until 600 years later because that’s how long it’ll take the light from it to reach us. Has it happened already? Is tonight the night that light will reach us, and we’ll look up and see one of the brightest and rarest things in the galaxy shining at us from Orion’s shoulder? Probably not, but you never know. You feeling lucky?
Now, look a little further down, closer to the horizon by a little more than 10°; maybe a bit more than the width of a fist at arm’s length. See those three stars that make up Orion’s sword? Look closer. <sing> The middle one is a little hazy, a little fuzzy and blue. It isn’t a star at all; it’s the Orion Nebula, Messier 42. </sing> Nope, I didn’t mean for that to rhyme. The Orion Nebula is a huge — something like 25 light years across — complex of collapsing gas, where stars form. It’s the closest one of these to us, and one of the only ones, if not the only one, visible to the naked eye from Earth. It’s really cool to see. If you have a pair of binoculars, it’s absolutely stunning, jaw-dropping, even from light-polluted cities. You’ll be able to see the cloud of gas and dust with the small Trapezium cluster at its middle. The stars Trapezium formed in the nebula, and are really young, possibly only about 300,000 years old.
The stars in constellations aren’t usually related to each other. They just seem to be because our eyes and brains have evolved to become really great at picking out patterns and familiarity, and making connections where they might not exist. Think about this for a second and try to get an idea of what you’re looking at when you see Orion. Betelgeuse is a huge star at the end of its days, and just ten degrees or so from your vantage, but in reality twice as far away, is a stellar nursery with young stars on their way off into the galaxy. It’s incredible, every bit of it.
There’s a lot to be said about this part of the sky, and loads to look at; plenty for lots of other posts, but this is a good start. I’ve made it no secret that I hope I never get tired of looking at Orion and Taurus. Each spring, when it disappears into the dusk, I’m always sad to see them go, but it’s like seeing old friends when they come back again in the fall. If you have a chance, go take a look. Now’s the perfect time to do it.
Clear skies, everyone!