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

3.9 The New Horizons mission

Described image
Figure 61 Global view of Charon and a close-up obtained at a range of only 79,000 km. 

Pluto’s moons were revealed in detail in 2015 when the New Horizons mission flew past Pluto. Launched in 2006, its journey to Pluto took nine years, and radio signals transmitted back to Earth took about four-and-a-half hours to reach us. It showed that Pluto’s landscape is unlike that of Triton, even though they have similar compositions. Charon has a mixture of cratered (old) terrain and smooth (young) terrain that might have been cryovolcanically resurfaced, and is cut by major fractures.

Despite searching, New Horizons did not find any new small moons, but it did discover that the rotation axes of the four previously-known small moons point in various directions and that their rotation periods are much shorter than their orbital periods (so these are not in synchronous rotation, unlike Charon). Here are views of Nix and Hydra shown at similar scales.

Described image
Figure 62 Nix (left), 42 km long and Hydra (right), 55 km long. The colour on Nix has been exaggerated to highlight an unexplained red area.

You can follow the mission at this link: New Horizons [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]

See also:

MOONS_BOC_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