Pass the Cereal—Milky Way May Become Galaxy-Sized Snack

It's been well-documented that massive galaxies often turn to extremes when star production ceases in their bounds of space. Turning their sights on consumption versus production, these super galaxies begin chowing down on nearby galaxies instead, pulling their growing solar systems into their own gravitational pull for themselves.

According to a new study published in the journal Monthly Notices of the Royal Astronomical Society, researchers have shown that galaxies may resort to cannibalism when stellar production comes to a halt.

"All galaxies start off small and grow by collecting gas and quite efficiently turning it into stars" lead researcher and postdoctoral associate at the international Centre for Radio Astronomy Research, Aaron Robotham says. "Then every now and then they get completely cannibalized by some larger galaxy."

As galaxies grow, forming new stellar components and matter out of gas, the larger masses induce even stronger forces of attraction; gravitational fields that can often disrupt neighboring planets and constellations. Productivity reaching a tipping point in these larger galaxies does not often point towards an end for them, but rather an end for its neighbors, as the galaxy continues to expand.

The international research team derived a new model to fully describe stellar mass dependence on close galactic pairs and mergers. Conservatively estimating the robust merging systems close to home, the researchers estimate that our very own Milky Way Galaxy may be nearing a few mergers in the future, as in cosmic terms, we recently surpassed the tipping point.

"The Milky Way hasn't merged with another large galaxy for a long time, but you can still see remnants of all the old galaxies we've cannibalized" Robotham says. "We're also going to eat two nearby dwarf galaxies, the Large and Small Magellanic Clouds, in about four billion years."

But after that, though our species may be long gone, the Milky Way will be in trouble of losing itself to another. Merely 1 billion years later, 5 billion years from now, the much larger Andromeda galaxy may engulf us in a super-giant galactic merger.