The Milky Way galaxy: our home among billions of stars
How many stars our galaxy holds, how big it is, where the Sun sits, the giant black hole at its centre and how to see the Milky Way in the night sky.
Rohit Tandon · 20 October 2026 · 4 min read
On a dark, clear night, far from city lights, you can see a faint, milky band of stars across the sky. In ancient India it was seen as a Ganga flowing through the sky, so it was named "Akashganga". In English it is called the Milky Way. It is not a cloud but our own galaxy — the vast family of billions of stars in which our Sun is just one star.
The Milky Way at a glance
| Item | Details |
|---|---|
| Type | A spiral galaxy, with a "bar" of stars across its centre |
| Diameter | About 100,000 light years |
| Stars | An estimated 100 to 400 billion |
| Sun's distance from the centre | About 26,000 light years |
| At the centre | The giant black hole "Sagittarius A*" |
| One orbit of the Sun | About 230 million years (a "galactic year") |
What is a light year?
Distances in the galaxy are hard to measure in kilometres, so the "light year" is used. Light travels about 300,000 kilometres in a second, and the distance it covers in a year — about 9.46 trillion kilometres — is called one light year. Remember, a light year is a unit of distance, not time. Even light would take about a hundred thousand years to cross the Milky Way from one edge to the other.
Where is our Sun?
The Milky Way is like a spinning pinwheel with several spiral arms. Our Sun lies about 26,000 light years from the centre, in a small branch called the "Orion Arm" — roughly halfway between the centre and the edge. The Sun, with all its planets, is circling the centre of the galaxy. One orbit takes about 230 million years; the last time the Sun was in this spot, the age of the dinosaurs was just beginning on Earth.
Did you know? At the centre of the Milky Way is a giant black hole named "Sagittarius A*", with the mass of about 4 million Suns. On 12 May 2022 the "Event Horizon Telescope" released the first image of it. The 2020 Nobel Prize in Physics was also awarded for work connected with its discovery.
Our neighbour: the Andromeda galaxy
Our largest neighbouring galaxy is "Andromeda", about 2.5 million light years away. In a very dark sky it can be seen even with the naked eye as a faint smudge — among the most distant things visible without a telescope. Andromeda and our Milky Way are moving towards each other, and billions of years from now they may collide and merge into one large galaxy. The whole universe contains billions of such galaxies.
How to see the Milky Way
- Go far from city lights, to a place where the sky is truly dark.
- Choose a night near the new moon, when there is no moonlight.
- Give your eyes 20–30 minutes to get used to the dark, and avoid your phone's light.
- In India, Hanle in Ladakh became the country's first "Dark Sky Reserve" in 2022, and the Milky Way is seen very clearly there.
To understand the night sky, read Why the pole star never moves and How to watch a meteor shower. About the solar system: The 8 planets of the solar system.
Key points
- The Milky Way is our own galaxy, and the Sun is one of its stars.
- It holds an estimated 100 to 400 billion stars.
- Its diameter is about 100,000 light years.
- At its centre is a giant black hole called Sagittarius A*.
- Our largest neighbouring galaxy is Andromeda.
Frequently asked questions
What is the name of our galaxy?
The Milky Way, called "Akashganga" in Hindi.
What does a light year measure?
Distance — the distance light travels in a year, about 9.46 trillion kilometres.
More articles: Science · Science questions.
Sources
Found this useful? Share it.