Moons of our Solar System
Moons of our Solar System

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

Moons of our Solar System

1.5 Lunar mantle fragments at the surface

The SELENE mission was a Japanese lunar orbiter, launched 14 September 2007. The scientific objectives included obtaining information about the chemical composition of the lunar surface and studying the formation and geological evolution of the Moon. You will learn more about the SELENE mission next week.

The spacecraft measured the reflectance spectra of the lunar surface over a broad range of wavelengths and with a spatial resolution of around 500 m, in order to map the global distribution of the mineral olivine. The magma ocean hypothesis predicts that the mineral olivine should dominate the upper mantle and therefore should not be common in the lunar highlands. However, 34 olivine-rich sites were identified and all were concentrated around large impact basins located in thinner parts of the lunar crust. The presence of olivine is believed to be a result of exhumation of upper mantle material during large impacts, suggesting that olivine does occur in the upper mantle. No olivine was found in the thicker highlands crust.

Described image
Figure 3 An image of the lunar surface showing the sites where mantle olivine was detected. The high olivine sites are marked in green.

Activity 1 Test your knowledge on the structure of the Moon

Timing: Allow approximately 15 minutes.
Figure 4 The Moon’s interior.

Try to work out which layer each empty label refers to.

When you’re ready, select ‘Reveal answer’ to see a fully labelled version.

Choose from these options:

  • inner core
  • outer core
  • mantle
  • lunar surface
  • partial melt
  • crust.


Figure 5 The Moon’s interior, with labels.

See also:

  • Chang’e 4 landing [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] The China National Space Agency landed its Chang’e 4 probe on the far side of the Moon on 3 Jan 2019. This is the first ever far side landing. The landing site is in the South Pole Aitken basin, and there is a chance that Chang’e 4’s rover (Yutu 2) may find fragments of mantle. Read David Rothery’s article here.
  • Misleading red colour in the first Chang’e 4 images A demonstration of why the early colour images from Chang’e 4 showed the lunar surface looking too red (later images from the science cameras were correct).

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