text: Venus is one of the closest planets to resemble Earth in the entire solar system. The author states, "Venus is the closest planet to Earth in terms of density and size..." This is the author's way of introducing the idea that other planets in our solar system could have been able to harbor some form of life at some point. The author also states, "Astronomers are fascinated by Venus because it may well once have been the most Earth-like planet in our solar system. Long ago, Venus was probably covered largely with oceans and could have supported various forms of life, just like Earth. Today, Venus still has some features that are analogous to those on Earth. The planet has a surface of rocky sediment and includes familiar features such as valleys, mountains, and craters." The author uses these excerpts in order to explain to the reader why there is such a fascination with studying Venus and why he supports it.