Galaxy, that have billions of stars and billions billions planets. All these stars and planets held together by gravity and all are rotating even a galaxy can rotate.
Milky way galaxy:- We are living in Milky Way galaxy. All the stars that are visible in the sky are in milky way and our sun is a part of these stars.
There are billions of galaxies in the universe. Every Galaxy have different shape and size. The shape of galaxies are like Spiral galaxy, elliptical galaxy, irregular galaxy.
Aur Galaxy, the Milky Way is a spiral galaxy.
Visible galaxies from earth:- Through billion of galaxies, only three galaxies can be seen from earth. One of them is andromeda galaxy, which is 2.2 million light year away and it is the nearest galaxy to us.
According to scientists, clumps of dust and gases joined together to form stars planets and then a galaxy. That’s why most of the stars and planets are made of gases.
The Milky Way is a huge Whirlpool shape galaxy have billions of stars, dust and gases. Even light can take 100000 years to cross it from one end to another.
Some scientists thinks that there is a super massive black hole in the centre of our galaxy and the revolutions of that black hole are not so fast. That’s why milky way is stable.
Our solar system that have Sun, planets, etc. is only a tiny part of Milky Way galaxy and the milky way is a tiny part of the universe.