# How do scientists know how big the galaxy is?

## How do scientists know how big the galaxy is?

Scientists work out how large the universe is by paying attention to each little measure meant eg. And they measured the Milky Way to be a staggering 100 000 light years long from end to end! Then they zoom out into the local group of 54 galaxies which is about 10 MILLION light-years across!

How do astronomers determine the shape of a galaxy?

A space probe moving at near light speed would take thousands of years to get far enough away to take a parting snapshot. But we can infer the shape of our galaxy by looking outward into space – toward tens of billions of other galaxies.

### Is our galaxy Big or small?

Size and mass The Milky Way is the second-largest galaxy in the Local Group (after the Andromeda Galaxy), with its stellar disk approximately 170,000–200,000 light-years (52–61 kpc) in diameter and, on average, approximately 1,000 ly (0.3 kpc) thick.

How do you identify a galaxy?

Galaxy classification Galaxies are classified by shape. There are three general types: elliptical, spiral, and irregular. Perhaps the most familiar kind of galaxy are spiral galaxies. They have a distinctive shape with spiral arms in a relatively flat disk and a central “bulge”.

#### How old is our galaxy?

13.51 billion years
Milky Way/Age

Astronomers believe that our own Milky Way galaxy is approximately 13.6 billion years old. The newest galaxy we know of formed only about 500 million years ago.

How big is the entire universe?

The proper distance—the distance as would be measured at a specific time, including the present—between Earth and the edge of the observable universe is 46 billion light-years (14 billion parsecs), making the diameter of the observable universe about 93 billion light-years (28 billion parsecs).

## How did we find out what the galaxy looks like?

The clues we have to the shape of the Milky Way are: 1) When you look toward the Galactic Center with your eye, you see a long, thin strip. This suggests a disk seen edge-on, rather than a ellipsoid or another shape. We can also detect the bulge at the center.

Do we actually know what the Milky Way looks like?

Shapley concluded (and other astronomers have since verified) that the center of the distribution of globular clusters is the center of the Milky Way as well, so our galaxy looks like a flat disk of stars embedded in a spherical cloud, or ‘halo,’ of globular clusters.

### How does galaxy look like?

What does our Galaxy look like? We live in the Milky Way Galaxy, which is a collection of stars, gas, dust, and a supermassive black hole at it’s very center. Our Galaxy is a spiral galaxy, which are rotating structures that are flat (disk-like) like a DVD when looked upon edge-on.

What are the 4 types of galaxies?

In 1936, Hubble debuted a way to classify galaxies, grouping them into four main types: spiral galaxies, lenticular galaxies, elliptical galaxies, and irregular galaxies.

#### What is the oldest thing in the universe?

Astronomers have found the farthest known source of radio emissions in the universe: a galaxy-swallowing supermassive black hole.

How big is the Milky Way compared to our Solar System?

When we leave the solar system, we find our star and its planets are just one small part of the Milky Way galaxy. The Milky Way is a huge city of stars, so big that even at the speed of light, it would take 100,000 years to travel across it.

## How big is the universe beyond our own galaxy?

Beyond our own galaxy lies a vast expanse of galaxies. The deeper we see into space, the more galaxies we discover. There are billions of galaxies, the most distant of which are so far away that the light arriving from them on Earth today set out from the galaxies billions of years ago.

How many stars are in the Milky Way galaxy?

There may be a hundred billion galaxies in the Universe. A galaxy is full of stars: Our sun is just one of at least a hundred billion stars in our own Milky Way galaxy. FAQ: How Big is Space? FAQ: How Big is Space?

### Is the universe bigger than our Solar System?

The universe is a vast expanse of space which contains all of everything in existence. The universe contains all of the galaxies, stars, and planets. The exact size of the universe is unknown. Scientists believe the universe is still expanding outward. Go farther. Explore Beyond Our Solar System In Depth ›