If you need some good news in your day, consider the recent findings that our Milky Way galaxy most likely won’t suffer a grisly fate. At least, not a specific kind of grisly fate. Probably.
For years, scientists have wondered whether collisions between the Milky Way and its satellite galaxies might someday tear apart the Milky Way. Luckily, Stelios Kazantzidis and his colleagues recently published a paper in the Astrophysical Journal that puts such fears to rest.
They performed simulations of such collisions with an unprecedented level of detail and concluded cheerfully that the satellite galaxies would disintegrate slowly and leave intact the larger galaxy. The satellite galaxies’ gravity would pull at the edges of the larger one, though, drawing out stars and gases, and eventually resulting in a flared or puffy look around the galaxy’s edges.
In fact, the result answers another question astronomers had, namely, “How did the Milky Way get those puffy, flared edges?” Looks like it’s the result of satellite galaxy collisions, which have apparently been going on for some time.
Of course, Kazantzidis can’t offer a 100-percent guarantee that our galaxy’s safe, but for now the data looks pretty good. What a relief, the Milky Way won’t be destroyed in billions of years. Phew!
It reminds me of the old joke, where an astronomer says to a friend, “You know, the Sun’s going to become a red giant in about 5 billion years, pretty much ending all life on Earth.”
The friend says, “What?! Did you say 5 million years?”
“No, 5 billion.”
“Oh, thank goodness.”
So, did this galactic reprieve brighten your day? Or did the reminder that Earth will probably be devoid of life in “just” 5 billion years bum you out?
Photo Courtesy Stelios Kazantzidis, Ohio State University