Hi there. Well done for getting to Week 2. Last week we had a first look into moons and their orbits. I think my favourite part was the 'Waltz around Saturn' - the video of Saturn's moons set to music. Much of my work is focused on laboratory analysis of samples, but every now and then it's good to be reminded just how simply beautiful moons can be.
This week you'll discover what moons are made of and how - like a planet - they can have an internal layered structure. By which I mean a core, mantle and a crust. You'll find that moons in the outer Solar System, at Jupiter and beyond, tend to contain a higher proportion of ice and the ice is so cold, it behaves essentially like rock.
You'll also discover that ice isn't just frozen water. It can be the frozen form of substances that are more familiar to us on Earth as gases, such as methane and carbon dioxide. Further from the Sun the cocktail of ices on the moons gets richer, which is another reason why this sort of ice behaves like rock does within the Earth.
Then we'll look at craters. Craters are really interesting. On our Moon - like on other moons - we've learned that they have been formed as the result of large meteorite and comet impacts. In the final hour this week we'll see how impacts occurring on the Moon can actually be observed, and what these observations tell us. We've built a simulator - actually a bit of a game, that allows you to work out the size of a crater that would be formed on different moons by particular impactors. See you next week.
Making the decision to study can be a big step, which is why you'll want a trusted University.
The Open University has over 40 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, find out more about the types of qualifications we offer, including our entry level
Access courses and Certificates.