It’s possible the Milky Way is starving to death or already dead, but a part of our galaxy that was exiled into space millions of years ago is now barreling its way back home. When it arrives, it may bring with it a snack that could revive the galaxy.
Unless you spend your days studying the life cycle of stars, you’re likely confused right now, so let’s break that down less metaphorically.
Galaxies like our Milky Way grow by “feeding” off of a cosmic supply of hydrogen gas to form new stars. When the process of star formation in a galaxy begins to slow down or stop, scientists like Kevin Schawinski from the Swiss Federal Institute of Technology refer to that galaxy as dead or dying.
Schawinski has been drawing on a crowd of willing volunteer citizen scientists on Galaxy Zoo to try and determine if the Milky Way is in fact in the midst of a terminal decline. The results are uncertain. Our galaxy appears to be teetering on the edge of a cliff about to fall toward its inevitable end, he says, if it hasn’t already gone over.
“It’s entirely possible that the Milky Way galaxy is a zombie, having died a billion years ago,” he wrote on Thursday on academic outreach site The Conversation.
On the very same day, a team based at Notre Dame detailed findings that a big shipment of that galactic “food” needed for continued growth via star formation is hurtling toward us at 700,000 miles per hour (about 1,126,500 kilometers per hour).
- ‘Bent light’ offers glimpse of huge galaxy 11.7 billion light years away
- Spotted in space: An explosion far brighter than the entire Milky Way
- Mysterious galaxy cluster looks like a cosmic finger painting
- The Milky Way was probably even more dazzling in its youth
- Cosmic effort provides best view yet of distant colliding galaxies
Specifically, the cosmic feast is a giant gas cloud called the Smith Cloud that was actually a part of the outer Milky Way some 70 million years ago before being mysteriously ejected into intergalactic space. Now, the Smith Cloud is boomeranging back home, and it’s carrying with it enough hydrogen and helium gas to create 2 million suns when it collides with the Milky Way.
“The cloud is an example of how the galaxy is changing with time,” explained team leader Andrew Fox of the Space Telescope Science Institute in a NASA release Thursday. “It’s telling us that the Milky Way is a bubbling, very active place where gas can be thrown out of one part of the disk and then return back down into another.”
While scientists continue to try and determine where the Milky Way is in its own lifespan, we can take some solace in the fact that a sweet shipment of star sustenance is on the way. Of course, we won’t be around when the Smith Cloud finally makes its homecoming. It’ll still be about 30 million years before it plows into the edge of our galaxy.