Two nights ago I was out with a group under the sky at 11 o’clock. We were a good distance from city lights with dark sky all around. The W-shape of Cassiopeia stood high in the northeastern sky.
I love the W not just for its easy-to-recognize outline but because it can take you places. The farthest place it points is the most remote object typically visible with the naked eye – the Andromeda Galaxy.
The galaxy looks like an unassuming small, fuzzy patch of light, but don’t let it fool you. Andromeda is at least half again as large as the Milky Way galaxy and contains 1 trillion stars or more than twice as many as our galaxy. When you take all those riches and stash them 2.5 million light years away, only a hint of their grandeur remains. We can bring some of the galaxy’s spectacle back through photography. Our imagination does the rest, transforming fuzz into glory.
Like you, I enjoy looking at pictures of nebulas, galaxies, planets – you name it – taken with big scopes like the Hubble. But I’m never satisfied until I get a look at the real thing. The thought of tiny photons of light traveling all the way from a particular deep sky object straight into my own eyeballs gives my spine a sizzle. Who cares if it looks like nothing more than a pinpoint of light. If you know you’re staring at a supernova or Earth-approaching asteroid, reality wins.
That’s why you should go out the next clear night to find the Andromeda Galaxy. It’s not too hard to find. If you can see the hazy band of the Milky Way across Cassiopeia even faintly, Andromeda’s within your reach. Use the right side of the W as an arrow to point you to the galaxy. It’s a little more than one fist held at arm’s length away from the “pointing star”. I’ve picked out the galaxy from suburban areas here in Duluth, Minn.; it’s even easier from the countryside.
If you have any trouble at all, take along your binoculars. Heck, take them anyway. With just a little extra glass and magnification, Andromeda expands into a disk several times the size of the full moon. You’ll also be able to distinguish the galaxy’s central bulge, where most of its stars are concentrated, from the flat disk. Both Andromeda and the Milky Way are spiral galaxies with arms that wind around their centers. Other types of galaxies include ellipticals which are spherical to oblong but lack arms, and the ragtag “irregulars” that lack symmetry.
Since light takes 2.5 million years to reach your eye from Andromeda, I’ve often been asked whether we’re even sure it’s still there right now in 2012. The answer is yes! Compared to a galaxy’s lifetime of billions of years, a few million is just a drop in the bucket.
Care to see even farther? Not far from Andromeda in the constellation Triangulum the Triangle sharp-eyed sky watchers under very dark skies can spot M33, the Pinwheel or Triangulum Galaxy.
Catch it and you’re peering out another 200,000 clicks to 2.7 million light years. It’s faint but even my aging eyes can spot it under great skies. I’ve heard of some amateur astronomers pushing back the naked eye limit even further with sightings of the galaxy M81 in the Great Bear Ursa Major. That one’s nearly 12 million light years away!