Video: Earth as a planet
Earth is the largest rocky planet in our Solar System, and the only body we know of capable of supporting life. With so much news about exoplanets dominating the headlines, in this episode of Space we take a step back to take a look at Earth as a planet.
Four and a half billion years old and 149.6 million kilometres from the Sun, it's not like anything else in the Solar System: "Planet Earth is quite a particular planet," says Josef Aschbacher, Director of Earth Observation at ESA. "We have 70% of water, we have land masses which are actually moving over time. We have an atmosphere which is rich in oxygen, nitrogen, in water vapour. All of these are necessities in order to have life on a planet like this."
Rome is a perfect spot to look at the defining characteristics of planet Earth, in particular the presence of liquid water. Our home planet has the right temperature and correct atmospheric pressure for water to flow on its surface, making it so hospitable to life.