How can it be shown that galaxies other than the Milky Way exist?

Although we cannot visit the other galaxies we can see that they are there through telescopes—that’s how we know they exist. An astronomer called Shapley took the position that they were in our galaxy, while another astronomer called Curtis argued that they were outside it.

Are there more stars in our galaxy or more galaxies in the observable universe?

Now the next step. Using the Milky Way as our model, we can multiply the number of stars in a typical galaxy (100 billion) by the number of galaxies in the universe (2 trillion). The answer is an absolutely astounding number. There are approximately 200 billion trillion stars in the universe.

Why do we believe that our galaxy contains a large amount of dark matter?

Unlike our Solar System, whose mass is dominated by the Sun, mass in our galaxy is spread across thousands of light years. One possibility is that a vast amount of unseen mass extends beyond the stars and gas. This is dark matter.

Are there stars in between galaxies?

Although stars cannot form in the voids between galaxies (since the density of matter is far too low), there are in fact large numbers of ‘intergalactic stars’. It has been estimated, for example, that 10 per cent of the mass of the Virgo galaxy cluster is in the form of these stellar interlopers.

Are all stars suns in other galaxies?

There are about 200 _ 400 billion stars in milky way galaxy. There are billions of such galaxies in this universe. Sun is a star..all stars are like Sun but some may be larger or smaller. Mily way galaxy is about 100,000 light years in size stars are different in size, age, temperature etc..

How does gravitational lensing prove dark matter?

Although astronomers cannot see dark matter, they can detect its influence by observing how the gravity of massive galaxy clusters, which contain dark matter, bends and distorts the light of more-distant galaxies located behind the cluster. This phenomenon is called gravitational lensing.

What are the characteristics of galaxies?

Galaxies are huge spans of gas, dust, dark matter, and from a million to trillions of stars. Everything in a galaxy is bound by gravity. Each star in a galaxy is a sun and there are thousands of solar systems in every galaxy.

Are galaxies held together by gravity in clusters?

In clusters, galaxies are held together by the force of gravity. If a cluster contains numerous galaxies, then it is a supercluster. The Milky Way is a part of the Local Group cluster which contains more than 50 other galaxies. How is gravity important to the galaxies within our universe?

How were galaxies formed after the Big Bang?

There are two theories about how galaxies were formed after the Big Bang. According to one theory, gravity pulled gas and dust together to make stars and planets, which were drawn together to create galaxies. According to the second theory, the universe already contained “clumps” of matter, that gathered together to form galaxies.

Why are some galaxies irregular in shape?

It’s believed that their lack of specific shape is due to being influenced by other galaxies that are close to them. Irregular galaxies are filled with dust and gas and due to this fact, they are perfect as star nurseries.