Exploring Mars

The first robots to land on the planet Mars were the two Viking landers, Viking 1 and Viking 2, in the 1970s. The (7).......... they were sent was to look for signs of life. They were programmed to carry out various experiments, and, at first, it seemed the results were positive. In the end, however, scientists decided the results did not (8).......... for sure that there was life on the planet.

There are (9).......... five robots working on Mars today, and these are called rovers. The advantage of rovers over landers is that rovers can travel across the surface collecting information from different areas. One of these rovers, Curiosity, has been on Mars since 2012. During that time it has discovered that there used to be large (10).......... of water on the planet, and that the planet’s soil (11).......... the chemicals that are necessary for life to exist.