Experts say the Milky Way is dying or have actually already died, implying that we are already living in a zombie galaxy. There is a way to bring it back from the undead though, as a giant cloud of fiery gas is on its way to save the day.
Kevin Schawinski, a professor from Swiss Federal Institute of Technology Zurich collaborated with citizen scientists to help him classify galaxies, particularly its shape.
Schawinski gets a consensus about the shape of the galaxies and delve into how this classification influences the lifespan of galaxies.
As he goes through with his investigation, he realized that the Milky Way may be slowly shutting down or may have completely died many years ago.
"It's entirely possible that the Milky Way galaxy is a zombie, having died a billion years ago," he writes.
Food For Galaxies
Galaxies thrive through a supply of hydrogen gas so it can form new stars. When this food supply runs out and star formation stops, then it is a signal that the galaxy is about to reach its end.
Gas conversion continues just like in factories, but imagine the day when the supply of raw materials, or in the case of galaxies, fresh outside gas, runs out. What is there left to process? Such possibility leaves just the remaining gas and its reservoir.
Since the reservoir is massive and the gas formation is slow, just like in the Milky Way, it continues to look alive with new stars. The truth is, the rate of star formation plummets over several billion years.
Green Valley
There are two types of galaxies in terms of star formation. The first one is the blue star-forming galaxies and the red passively-evolving galaxies. There is another one and it is represented by the green color.
Galaxies living in the so-called "green valley" have star formations in the brink of turning off. Star formation still continues, indicating that the process has just stopped, probably a hundred million years ago. The Milky Way may possibly belong to this category.
Help On The Way
A new capture of the Hubble space telescope implies that help is on the way for our dear, dying galaxy. The telescope was able to detect a giant cloud of fiery gas that can help the galaxy continue its star formation and survive.
Called the "Smith Cloud," this giant gas is hurtling towards the Milky Way at 700,000 miles per hour. Experts say it may be a part of the Milky Way 70 million years ago and is now boomeranging home with a large bag of goodies: sufficient hydrogen and helium gas supply that is enough to form 2 million suns.
"The cloud is an example of how the galaxy is changing with time," says Andrew Fox from the Space Telescope Science Institute.
Whether there is truth to the Milky Way being at the edge of the green valley or not, people may find peace in the fact that the Hubble was able to detect the Smith Cloud, which will hit the galaxy about 30 million years from now.
