January 4, 2019
A Nearby Galaxy Will Collide With Our Milky Way In A Few Billion Years, Scientists Say

According to a new paper in the Monthly Notices of the Royal Astronomical Society, a nearby galaxy called the Large Magellanic Cloud (LMC) is on a crash course with our Milky Way that could destabilize our solar system and doom life on planet Earth, should any life be left by the time the event occurs. As reported by the Guardian, the paper estimates the collision will take place within the next 2 billion years

Previous tracking on the Large Magellanic Cloud had the satellite galaxy orbiting the Milky Way harmlessly, but new simulations run by astrophysicists at Durham University see the galaxy slowing down and "crashing" into the Milky Way. Of course, space is vast enough that it is unlikely any stars or planets would actually smash together, but that won't stop the eventual merging of galaxies from having "secondary effects" that could screw things up for Earth.

Inverse spoke with cosmology researcher Marius Cautun, who was first author on the new paper. He notes the effect a merge would have on the orbit of stars in the Milky Way, which would, in turn, affect the orbits of planets surrounding those stars. Should any of the new star trajectories take them close enough to our sun, it could knock all of the planets in our solar systems out of whack.

"Any such change is very dangerous for life," Cautun said. "Since even small variations in the distance between the Earth and the Sun can move our planet outside the Goldilocks zone and make it either too hot or too cold for life."

The 30 Doradus Nebula, a fertile star-forming region is seen in this panoramic mosaic portrait released by NASA July 26, 2001 of a vast, sculpted landscape of gas and dust where thousands of stars are being born. This image of 30 Doradus, as seen through NASA''s Hubble Space Telescope, consists of five overlapping pictures taken between January 1994 and September 2000 by Hubble''s Wide Field and Planetary Camera two. 30 Doradus has a sparkling stellar centerpiece, the most spectacular cluster of massive stars in our cosmic neighborhood of about 25 galaxies.
Getty Images | NASA
The 30 Doradus Nebula, a fertile star-forming region in the Large Magellanic Cloud.

On the worst case scenario side of things, Cautun notes there's also a 1 to 3 percent chance our solar system could be one of many stars ejected from the galaxy during the merge.

As scary as all this sounds, galaxies crashing into each other is a common occurrence and Cautun told Inverse that the Milky Way is "long overdue" for a galactic mash-up. Before his research factored in a halo of dark matter surrounding the Large Magellanic Cloud that set us on this path, the Milky Way was expected to eventually run into the Andromeda galaxy, which Space reports has already swallowed up hundreds of smaller galaxies over the eons.

Merging into the much larger Andromeda galaxy would be way worse for the Milky Way, Institute for Computational Cosmology director Carlos Frenk told the Guardian.

"The LMC is big but it won't completely destroy our galaxy," Frenk said. "It'll produce these amazing fireworks, but it doesn't have the mass to create a huge disturbance. The collision with Andromeda really will be Armageddon. That really will be the end of the Milky Way as we know it."

That unfortunate event was originally estimated to take place some 4 billion years from now, but new calculations will be needed to factor in the earlier impact of the Milky Way and Large Magellanic Cloud. According to Frenk, that collision could buy earthlings a couple extra billion years.