Fun little-known facts about the Milky Way

Although you know all your favorite restaurants and how to avoid traffic jams during rush hour, you're not sure you know every corner of the city. The same is true of the galaxy you live in - the Milky Way.

Our galaxy is amazingly full of stars, supernovas, nebulae, dark matter and energy, but many aspects of it remain mysterious - even to scientists. For those who want to learn more about the universe we live in, here are some interesting facts that few people know about the Milky Way.

1. The name of the Milky Way has a very ancient origin

Before the electric light came out, people could see the sky very clearly at night, and the giant star strip filled with stars could easily meet our eyes. Ancient peoples have given different names to the Milky Way, but the name used now comes from Greece. Greek legend tells of a newborn baby named Hercules being taken to the goddess Hera to take care of. Once she was feeding Hercules, she fell asleep. When she awoke, she sat up and the milk poured from her breasts across the sky.

The origin of this name has long been forgotten, like Matthew Stanley, a professor of science history at New York University, who said: "This is one of the terminology so old that its origin is often forgotten".

2. It is not possible to know exactly how many stars are in the Milky Way

Perhaps the Milky Way contains about 100 billion stars.(Image: Two Micron All-Sky Survey)

Counting stars is a tedious task. Even astronomers argue in order to find the best way to do it. The current telescope can see only the brightest stars in the galaxy, and the rest is obscured by gas and dust. One technique for estimating the Milky Way's 'star population' is to see how fast stars orbit, from which we will know the mass of the galaxy. Divide the galaxy mass by the average size of a star and you'll get the answer.

But as David Kornreich, an astronomer at Ithaca University in New York, once said: these numbers are approximate because stars are very different in size. Many assumptions have been made to estimate the number of stars residing in the Milky Way. The European Space Agency's Gaia satellite has mapped the positions of 1 billion stars in our galaxy and scientists believe it is only 1% of the total, so perhaps the Milky Way contains about 100 billion stars.

3. No one knows how much the Milky Way is

For now, astronomers are still not sure how much our galaxy is, they only estimate it is 700 billion to 2 trillion times heavier than the sun. To have a more accurate number is not an easy task. Most of the Milky Way's mass - perhaps 85% - is in the form of dark matter, which emits no light and therefore cannot be observed directly, says astronomer Ekta Patel of the University of Arizona in Tucson. . Her recent research estimates that the Milky Way's mass is 960 billion times heavier than the sun.

4. The Milky Way is full of toxic grease

Grease-like substances can account for a quarter to half of the Milky Way's interstellar carbon.(Photo: NASA / JPL-Caltech).

Rotating in the empty space between stars in our galaxy is a mess of greasy oil. Oily organic molecules called aliphatic carbon compounds are produced in some types of stars and then leak out into interstellar space. A recent study showed that these greasy-like substances could account for a quarter to half of the Milky Way's interstellar carbon - five times more than previous studies have shown. While this may sound strange, it's good news to be optimistic about, because carbon is an essential substance of living things. Finding it abundantly throughout the galaxy may suggest that other star systems contain life.

5. The Milky Way will collapse in 4 billion years

It's sad to know that our galaxy will not last forever. Astronomers say our 'home' is now moving towards the 'neighbor' - the Andromeda galaxy, at a speed of about 250,000 miles / hour (400,000km / hour). Most research has shown that when the accident occurs, in about 4 billion years, the more massive Andromeda galaxy will swallow our Milky Way and survive.

But in a recent study, astronomers reconsidered Andromeda's mass and found that it weighed the equivalent of 800 billion suns combined, or equal to the mass of the Milky Way. That means exactly which galaxy will survive this future clash remains an open question.

• What is the Milky Way? What is the difference between a galaxy and a galaxy?
• The beautiful Milky Way video, showing how clearly the Earth is rotating