Our galaxy is a 'zombie'.

Scientists claim that the Milky Way where we live actually died billions of years ago because . hungry.

Our Andromeda neighbor galaxy is almost certainly "expired" several billion years ago but has just begun to show off the signs of collapse.

Similarly, our Milky Way galaxy is like a zombie, dead but still moving, so we haven't realized it yet. This is the analysis of Kevin Schawinski of the Swiss Federal Institute of Technology, posted on the academic website The Conversation.

Healthy living galaxies (left) and dead galaxies differ in the color of light emitted by stars - (Photo: CC BY-NC).

Galaxies are known as dynamic systems, continuously adding gas and converting them into stars. That's how the galaxy grows.

When stars reach the age of death, they return to gas to the galaxy through the wind from stars or supernovae.

Like humans, galaxies also need food. However, food of course different. For galaxies, delicious food is fresh hydrogen from the cosmic network - dark matter fibers and halo create the largest structures in the universe.

The death of the galaxy means it no longer has the gas to form new stars. Many galaxies such as the Milky Way and Andromeda are also "hungry" even though this process progresses slowly over billions of years.

It is recognizable by the naked eye that the galaxy dies or "spring colors" by comparing the color of the starlight emitted. Green galaxies are still active galaxies, living well, whereas red-shifting galaxies are caused by light emitted by older stars without a young star replacing the dead galaxy.

Between the two periods there is a transition point called "green valley". At this point, the galaxy is prevented from reproducing a lot but still acting lethargically. The galaxy in this state may have died about a hundred million years ago. But why they are no longer alive, unborn, and unchanging is still a big question of astrophysics.

Kevin Schawinski said the Milky Way is on the edge of "green valley" , meaning that it died millions of years ago, although it is still active now (Photo: CC BY-NC).

The researchers resorted to the help of other scientists through the Internet and worked to find out if our Milky Way was at this stage. The data collected revealed the Milky Way at the edge of the green valley, meaning that even though it was pretending, it actually died 1 billion years ago.

Kevin Schawinski said this was inevitable and it was "done" . He wrote: "It is entirely possible that the Milky Way is just a corpse, it has died billions of years ago".

But the same day, the hope of the Milky Way will revive thanks to the "food" supply that has appeared. A research team based in Notre Dame discovers a "shipment" - the food needed for the continual growth of the galaxy - flying towards us at a speed of 700,000 miles per hour (about 1 , 13 million km / hour).

The researchers believe that this giant gas cloud named Smith Cloud is actually part of the Milky Way about 700 million years ago. After that, it mysteriously separated from the galaxy. Currently, Smith Cloud seems to be a boomerang returning to his old place and how lucky he is to bring hydrogen and helium to the Milky Way.

"The cloud is an example of how galaxies change over time. It tells us," said study leader Andrew Fox of NASA's Space Telescope Science Institute . we know that the Milky Way galaxy is a ball, where gas is blown out and then back. "

While scientists are trying to determine the Milky Way's lifespan, we ourselves can comfort that, anyway, "food" for galaxies is on its way. Although of course, the distance that the "food bag" has to overcome is also far away, about 30 million years before reaching the edge of our galaxy.