A New Tell-All Memoir Written By The Milky Way
Astronomer and folklorist Moiya McTier’s new book is a saucy memoir that shows why our galaxy needed to tell its own story.
The following is an excerpt from The Milky Way: An Autobiography Of Our Galaxy by Moiya McTier.
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The Milky Way: An Autobiography of Our Galaxy by Moiya McTier
There are, of course, other galaxies besides me out in the universe, all of them less spectacular than me, with one remarkable exception. Most of those galaxies are tens of millions of light-years away and getting farther every second. But some galaxies—your astronomers have discovered about fifty so far—sit right beyond our galactic backyard, so to speak. As with any neighborhood, its quality depends on the people who live here, and we have a rather mixed bag.
They—we—are all gravitationally bound to each other. Only the most extreme case of universal expansion could drive us apart, and even that would take a couple dozen billion years. We are both literally and figuratively stuck with each other. Your human astronomers call our little gaggle of galaxies the Local Group.
The Local Group is about ten million light-years wide, surrounding its two most influential members: the galaxy you call Andromeda and, of course, me. Every other galaxy in the group is smaller than me, except maybe Andromeda, and most of them are less than 1 percent of my size. Those smallest ones don’t do much besides orbit larger galaxies with more gravity and responsibilities. They’re those neighbors who can’t be bothered to participate in anything—they don’t decorate for holidays or bring anything to the cookout or volunteer for the neighborhood watch or whatever else you humans do in your little communities— but they still soak up some of the resources. Except in our neighborhood, the only resource we really care about is inter- galactic gas.
I try not to think about these annoying hoverers much. Focus on them for too long and their persistent buzzing around my halo gets uncomfortable. You corporeal beings might call the sensation “itchy.” Your astronomers have observed the way my disk squirms and wiggles in response.
One particularly egregious pest is the dwarf galaxy your astronomers call Sagittarius, which ventured too close a few hundred million years ago, irking me until I started to tear it apart with my gravity. Now its stars are scattered around my body in the so- called Sagittarius stream, and I have its gas to snack on for eons to come. Smaller galaxies take longer to consume because their low masses make it difficult to get a good gravitational hold on them, but their defeat is always inevitable. Why bother making nice or even friends with a galaxy when I know I’ll just end up eating it in a billion years. Have you ever bared your soul to a bowl of hard candies?
But there are a few neighborhood galaxies who, over time, became what I guess you might call my friends. The biggest and brightest and most important of them is Andromeda, but I won’t give away too much of that story just yet. That leaves Larry, Sammy, and Trin, or as you probably know them, the Large Magellanic Cloud, the Small Magellanic Cloud, and Triangulum.
“Friends” is possibly too strong a word, and not always accurate. Do you have a word for a being whose presence you tolerate because its absence would lead to mind-shattering loneliness and despair?
You humans can actually spot all three of them with your weak naked eyes. Or at least your ancestors could see them before your species belched all kinds of pollution into Earth’s atmosphere.
Now you’d have to make a concerted effort to travel to some- where dark enough to catch a glimpse. Don’t feel bad if you’ve never made the trek. Only one of them even mildly deserves your attention, anyway. Of the other two, one is a jealous failure and the other is boring beyond belief.
Let’s start with the worst of them, shall we?
Like me, Triangulum has multiple names: Messier 33 (which your astronomers often shorten to M33), NGC 958, sometimes Pinwheel Galaxy, and my personal favorite, Trin the Underachiever. That last one isn’t recognized by your precious IAU, but it should be because it’s true! Trin is a little more than half my size and contains maybe a tenth as many stars, making it the third largest galaxy in the Local Group. This has always made Trin bitter.
I’m sure Trin would also be bothered—but certainly wouldn’t admit it—if I revealed that ancient humans didn’t include it in any of their stories. At least, none of the stories that were told loud or often enough for me to hear them, and they don’t appear to have survived to be heard by you. Trin is simply too dim to be of any widespread use.
The first human who even bothered to write about Trin in a way that was preserved was an Italian astronomer in the 1600s. Giovanni Battista Hodierna was an accomplished court astronomer who took excellent notes and knew noteworthy objects when he saw them, and he described Trin as some unnamed nebula “near the Triangle.” Any fuzzy patch in the sky was called a nebula back then, and the Triangle in question was the constellation now known as Triangulum. A little over a century later, Trin was added as the thirty-third item in the Messier catalog, a list of objects visible from your northern hemisphere by French astronomer Charles Messier. Hence the nickname M33. But do you want to know the best part? Back in your eighteenth century, Messier and his contemporaries were mostly interested in identifying comets, and Messier kept a list of all the frustrating objects that got in his way. And that’s the list Trin’s on! Ha! What a loser.
Trin sits on the other end of the Local Group, nearly three million light-years away from us, which is fabulous for me, but unfortunate for Andromeda, who has the—and I say this dripping with sarcasm, since I have no eyes to roll for you—pleasure of keeping Trin in orbit.
Trin has always sucked up to Andromeda, offering up streams of hydrogen and stars and following Andromeda like one of your lovesick puppy dogs. Unfortunately, Trin’s sad little courtship will bear fruit over time, because if they keep on their current path, the two galaxies will probably merge in about two billion years. It’s hard to be certain, though. The only thing I know for sure is that Andromeda would tear that sorry excuse for a galaxy to shreds and then remember that a much more appropriate companion is sitting patiently on the other side of the Local Group.
Excerpted from the book THE MILKY WAY: AN AUTOBIOGRAPHY OF OUR GALAXY by Moiya McTier. Copyright © 2022 by Moiya McTier. Reprinted with permission of Grand Central Publishing. All rights reserved.