Answer the following question given this paragraph: 

Mars is a lot like Earth. Mars is rocky and has an atmosphere. Mars even has water! But Mars (and Mercury, Venus, the Moon, Jupiter, Saturn, Uranus and Neptune) does not have any evidence of life. Life is what makes Earth unique. It is also part of Earth's dynamic nature. Life is part of many Earth processes. Life is also dynamic in itself. Constantly adapting and evolving, life forms are always changing. Except those that are so well adapted to their environment, they haven't changed in hundreds of millions of years.


Q: What is the only planet that is known to support life?


A:
earth