Seeing Andromeda for the First Time
Last night I saw the Andromeda Galaxy for the first time.
I did not really intend to do this. The sky just happened to be clear, so right before bed I took my binoculars to my porch. I let my eyes adjust to the dark and I noticed that the constellation Cassiopeia had returned to the sky; I hadn’t seen it since the springtime when I’d first learned about it and it went below the horizon. But a few minutes later, the thought occurred to me: Andromeda might be out, too.
The Andromeda Galaxy has about a trillion stars; it’s ~220,000 light-years across, ~2,500,000 light years away, and racing towards us at just below 250,000 miles per hour. Contrary to my previous misconception, Andromeda is larger than our own Milky Way. In galactic terms, it’s very close. It’s visible on clear, dark nights, but I hadn’t seen it yet because I began stargazing when it was out during the day. It is near Cassiopeia in the sky.
Risking losing my night vision, I pulled out my phone and opened my star-chart app. To my excitement, it said that the galaxy was (finally) above my nighttime horizon. I familiarized myself with the bright stars in the constellation before holding up my binoculars. I saw one red star (Mirach); then two white stars; and then, sure enough, spotted something white and fuzzy. Gotcha!
I saw no spirals or colors—that’s reserved for processed images or very good telescopes—but considering I was in an area with a lot of light pollution, I was satisfied with what was there. The galaxy was a fuzzy blob, as if someone had taken a bright star and smeared it around a bit. Although I couldn’t see the outer arms of the galaxy, its core was a bright ellipse. It was much larger than any of the surrounding stars and actually hard to miss.
Even though it was easy to spot, I still got excited. Other than the Orion Nebula, I hadn’t seen much in deep space with my own eyes. I’d been searching all summer long for galaxies and nebulae with little success. My nemesis, the ever-invisible Pinwheel Galaxy, seemed to be laughing at my futile attempts to spot it; the North American Nebula stayed elusive to everything but my camera. I probably did three double-takes just to check that I was actually seeing Andromeda and not anything else. I was, which made me happy.
But I wasn’t done yet. Another object I saw last night was the Lagoon Nebula. To see it, you have to look near the Milky Way’s core (and not out into space)… and it appeared fuzzy, too.
I stood there for a few more minutes, switching between these two targets. I’d have to swing my body 180 degrees to make the swap. But after a while of holding my binoculars, staring at clouds light-years across, I realized something cool. These objects were not arbitrarily positioned!
I love sanity checks like this. It makes sense that these two objects are on opposite sides of the sky. After all, the Andromeda Galaxy is in deep space, so we’d need to face away from our own galaxy to see it. But the Lagoon Nebula—a star-forming region—lies closer to the Milky Way’s center than we do, because the stars are denser there.
Sometimes in learning, I get so focussed on a single thing—like how to spot a galaxy—that it’s relieving to step back and see the big picture. It pays to be wary if everything always makes sense, but moments where you make connections to that big picture usually indicate that you’re on the right track.
Eventually the clouds rolled in, but I was tired anyways. I’d been swinging myself in circles for a while.