SOLAR SYSTEM

Detailed explanation-1: -Stars appear in the sky in the form of clusters called galaxies. Galaxy contain several million of stars. Their size can range from few thousands to several hundred thousand light years.

Detailed explanation-2: -Our galaxy, the Milky Way, is typical: it has hundreds of billions of stars, enough gas and dust to make billions more stars, and at least ten times as much dark matter as all the stars and gas put together. And it’s all held together by gravity.

Detailed explanation-3: -A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form.