The galaxy we live in, the Milky Way, will one day become a cosmic meal for Andromeda. Don’t worry, none of us will be around to see it. The Milky Way has about 5 billion years before it becomes Andromeda’s lunch.
Hopefully, the human race has moved on from bigger iPhones and have figured out a way to get somewhere else before that happens.
Why does Andromeda have it out for us? A new study published in the Monthly Notices of the Royal Astronomical Society says galaxies sometimes turn on one another once they get too big.
“All galaxies start off small and grow by collecting gas and quite efficiently turning it into stars,” Dr Aaron Robotham, leader of the research, said in a statement.
“Then every now and then they get completely cannibalized by some much larger galaxy.”
Before we become Andromeda’s lunch, we’ll be snacking on our own galaxies. “We’re also going to eat two nearby dwarf galaxies, the Large and Small Magellanic Clouds, in about four billion years.”
As galaxies become bigger, they generate more gravity and start pulling on neighboring galaxies. The size of a galaxy also affects its ability to generate stars. Why this happens is still being debated but as Robotham explains, “a popular mechanism is where the active galactic nucleus basically cooks the gas and prevents it from cooling down to form stars.”
Eventually, all the galaxies and clusters are expected to merge into a handful of super-giant galaxies.
“If you waited a really, really, really long time that would eventually happen but by really long I mean many times the age of the Universe so far,” Robotham added.
Check out the video below to see what it may look like when the two galaxies collide.