With hundreds of billions of stars burning bright, ‘dead’ seems like a bit of an exaggeration. But every galaxy is headed for this fate, including ours.
As long as a galaxy is forming stars, it’s considered to be alive by astronomers.
Our Milky Way contains large star-forming regions, mostly along its spiral arms, indicating stellar life.
But other, mostly elliptical galaxies, stopped forming stars many billions of years ago.
These galaxies are called red-and-dead, because they don’t have any hot, young, blue stars associated with recent star formation.
Since the hottest, bluest stars burn through their fuel the fastest, an intrinsic red color is evidence that no new stars have formed for a long time.
The leading theory is that galaxies require gas to form new stars.
If no stars are forming, the galaxy must be gas-free.
When mergers and interactions occur, star formation accelerates, expelling the critical material.
Only by speeding through the intergalactic medium can all of the interior gas can be truly stripped away.
As the world warms, trees in forests such as those in Minnesota will no longer be adapted to their local climates. That’s where assisted migration comes in.
What do hot dogs, the Vatican, and the Large Hadron Collider have in common? They're all in our random fact roundup where we bring you some favorite facts about three subjects.