1. At the moment there is no evidence that life exists on Mars.
2. They left camp and went to explore the countryside to see what they could find.
3. With the use of satellites, TV can show news from anywhere in the world.
4. Scientists believe they will have to carry out further experiments.
5. The 60s and 70s were an exciting period for space exploration.
6. Humans are always looking for the existence of new life forms.