This research is part of the collaborative Asterochronometry project, funded by the European Research Council.
Interesting facts about the Milky Way galaxy that we call home
- It spans about 100,000 light-years across.
- It’s a barred spiral galaxy, like billions of other galaxies in this universe. About two-thirds of galaxies are spiral galaxies.
- The galaxy contains a bar across its center region. Hence the name barred spiral. This central bulge is surrounded by four large spiral arms that wrap around it. The Milky Way sits on the outer edges of one arm within a disk of cosmic material, such as stars and asteroids.
- The Milky Way also contains two smaller spurs. One of these is the Orion Arm, where the sun and solar system are located. The Orion Arm sits between the two major arms, Perseus and Sagittarius.
- The Milky Way constantly rotates, so the sun and solar system move with it. The solar system travels at an average 515,000 mph (828,000 km/h). This rate may sound lightning-fast, but it would still take around 250 million years for the solar system to travel around the galaxy.
- Astronomers named it the Milky Way because it appears as a milky band of light in the dark sky.
- Scientists estimate that our galaxy contains around 100 billion stars, though it’s difficult to know.
- It’s almost as old as the universe itself. Scientists estimate that our universe is around 13.7 billion years old; the Milky Way is approximately 13.6 billion. However, the disk and bulge didn’t form until about 10-12 billion years ago.
- The Milky Way is comprised of around 90% dark matter, which we cannot see. It’s made of 10% “luminous matter,” or matter that we can see with the naked eye. A large amount of dark matter creates an invisible halo around the galaxy, which causes the stars to orbit much faster than if they didn’t exist.
- There’s an Earth-sized planet floating aimlessly within the Milky Way!
Studying outer space is endlessly fascinating, and scientists are continually uncovering more about its mysteries. Recently, a team from Ohio State University discovered estimates of when and how the Milky Way formed. They believe it merged with a galaxy called Gaia-Enceladus about 10 billion years ago.
The researchers also used new astronomy techniques to identify the ages of nearly 100 red giant stars in the Milky Way. They found that the age of these stars is similar to those born in the former galaxy. In the future, they will take samples from larger groups of stars, which will help them better understand how the universe developed.