Of course, there's more than one life form in this universe
No. Of course not. The universe is big enough to hold earth and all the other planets in the Milky Way Galaxy and all other galaxies and the sun and the moon and the stars. There is no way that the universe could be smaller that Earth. =)
The entire solar system is in the milky way, with all the stars you can see.
There is no singular star in the center of the universe. Our universe is vast and does not have a center. Stars are spread throughout the universe in galaxies, and our sun is just one of the billions of stars in the Milky Way galaxy.
the milky way is a galaxy, there are billions of stars in the milky way galaxy
No. The Milky Way galaxy is just one of billions of galaxies in the Universe. Just like there are billions of planets in the Milky Way Galaxy, there are also comparable numbers of planets in other galaxies.
The Sun is one of approx. 200 billion stars in the Milky Way galaxy.
Population II stars are the oldest in our Milky Way. Population III stars were the first stars in the Universe, but have yet to be discovered. See related question
According to what Carl Sagan that is true
Our own galaxy has between 100 and 400 billion stars; there are hundreds of billions of similar galaxies in the OBSERVABLE Universe, and it is believed that the entire Universe is much, much bigger than the observable Universe (how much bigger, is not known). It seems that at least a large percentage of those stars have planets, which means they can be called "solar systems".
None that we know of. The Milky Way is a bit larger than the average galaxy, with somewhere between 500 billion to a trillion stars (it's difficult to know, because there are an unknown number of small and invisibly dim red or brown dwarf stars). We don't believe it possible that any single star to be much larger than about 150 solar masses.
There are estimated to be over 100 billion stars in our Milky Way galaxy alone, and there are billions of galaxies in the observable universe. It is impossible to accurately count the total number of stars in the universe.
After the Milky Way galaxy, there are many other galaxies in the universe. Some of the closest galaxies to us are the Andromeda galaxy and the Triangulum galaxy. Beyond these, there are billions of other galaxies in the universe, each containing billions of stars.