I was surprised to hear that scientists consider our Milky Way galaxy to be a zombie. Apparently it has stopped forming new stars and so its days are numbered. But don’t worry, it will be hanging on for quite a while.
Galaxies apparently “perish” – in other words, they stop turning gas into new stars – via two very different pathways, driven by very different processes. Fortunately, galaxies like the Milky Way do so very slowly; it takes billions of years.
How and why this happens is a major scientific mystery, but we may be on the brink of getting some answers, thanks in part to many citizen scientists who have combed through millions of galactic images to classify what’s out there.
If you would like to know more about the life cycle of galaxies and what we are learning about them, there is an excellent article on the EarthSky website, but it gets pretty technical. You can reach it at http://earthsky.org/space/is-our-milky-way-galaxy-a-zombie?utm_source=EarthSky+News&utm_campaign=bba3530499-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-bba3530499-394611693