The search for water on Mars
The search for water on Mars

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

The search for water on Mars

4.2 Viking 1 and 2: looking for life but finding water!

The two Viking landers carried numerous instruments with which to measure pressure, temperature and wind on the martian surface. However, they also carried three biology experiments, designed to look for signs of life, and an instrument – a gas chromatography-mass spectrometer (GC-MS) - that could measure the composition and abundance of organic compounds in the martian soil. Although the biology experiments did not provide evidence of the presence of living organisms, the GC-MS revealed that the soil contained up to 0.8% water!

Using other instruments on board the landers, the minerals in the soil were revealed to be iron-rich clay and water-bearing iron oxides. This was the first proof, measured directly on the surface of Mars, of minerals that can only form when liquid water is present. Once, in Mars’ history, there had been liquid water present.

The Viking 2 lander also observed a thin layer of frost on the martian surface that could only form if water vapour was present in the atmosphere (Figure 17). On measuring the atmosphere, 0.03 % water vapour was indeed identified. You will learn more about these measurements of the atmosphere in the next section.

Alas, despite these results, there was a decline in scientific interest in the planet with no missions for nearly two decades. During that time, attention turned to samples of the martian surface available here on Earth – martian meteorites.

This is a photograph of the martian surface taken by the Viking 2 lander. The horizon is sloping from left to right. The sky is a pale orange colour. The surface is covered in red-brown dust with red-brown boulders of various sizes. The surface between the boulders has a dusting of white, which is water ice.
Figure 17 Viking 2 image showing a thin layer of water ice frost on the martian surface at Utopia Planitia. Image credit: NASA.
WOM_1

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371