In the night sky: Orion
In the night sky: Orion

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

In the night sky: Orion

4.2.6 Comets

Described image
Figure 18 Halley’s comet. Image taken at the Kitt Peak National Observatory near Tucson, Ariz. on 7 May 2004.

Comets are clumps of dust and organic material bound together by ice, with an irregular shape and up to a few kilometres across.

Described image
Figure 19 The irregular shape of Halley’s comet. The ‘potato shaped’ nucleus of the comet measures roughly 15 kilometers across.

When the European Space Agency’s Giotto mission photographed Halley’s comet in 1985, it was the first time that the irregular shape of a cometary nucleus had been observed.

Described image
Figure 20 Comet 67P/Churyumov-Gerasimenko.

In March 2004, the European Space Agency (ESA) launched the Rosetta spacecraft, with the goal of meeting up with comet Churyumov-Gerasimenko (named after its discoverers) in July 2014, flying alongside it for 18 months. This included dropping a lander (Philae) onto the comet’s surface which happened in November 2014.

Find out more about the Philae lander in the next section.

INS_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, find out more about the types of qualifications we offer, including our entry level Access courses and Certificates.

Not ready for University study then browse over 900 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 prospectus