Because they let us see further and discover what is out there in the Universe. Very importantly, they let us see back in time. Because light travels at 30,000 km per second, it means that light coming from a distant object takes time to get to us. The light we get from an object one billion light years away is one billion years old, so we are seeing the object as it was one billion years ago. In this way, we can see almost all the way back to the start of the Universe, 13.7 billion years ago. In this way, we can study the history of the Universe and how it evolved to get to this point.
Because they let us see further and discover what is out there in the Universe. Very importantly, they let us see back in time. Because light travels at 30,000 km per second, it means that light coming from a distant object takes time to get to us. The light we get from an object one billion light years away is one billion years old, so we are seeing the object as it was one billion years ago. In this way, we can see almost all the way back to the start of the Universe, 13.7 billion years ago. In this way, we can study the history of the Universe and how it evolved to get to this point.
0