ROCKS and ATMOSPHERES BEYOND EARTH

 Doc Brown's Chemistry - Earth Science & Geology Revision Notes for KS4 Science, GCSE, IGCSE & O Level Courses

[Author © Dr Phil Brown PhD: Doc Brown's chemistry exam revision notes suitable for students of UK GCSE Science level AQA, Edexcel, OCR, WJEC and CCEA GCSE science courses involving Earth Science, ~US grades 9-10 chemistry [page updated May 1st 2026 *]

INDEX OF EARTH SCIENCE PAGES

All my GCSE/IGCSE level chemistry revision notes

10. An extension! - Rocks and atmospheres on our moon and other planets - a few atmospheric and geological comments!

How does the geology of Earth compare with our own moon and the other planets? Why does the moon have no atmosphere? Why does the moon have no sedimentary rocks? Two reasons why Venus is much hotter than the earth.

Are the gas giant planets only made up of a mixture of gases? What do we no about the atmosphere and geology of our Moon, Mars, Venus, Mercury, Jupiter, Saturn, Neptune, Uranus and Pluto.

10. Extension! Rocks on the Moon and Planets

What atmosphere and rocks are out there beyond Earth?

10(a) The GAS GIANT PLANETS: On these planets (or any other except the Earth) there is no oxygen, so no photosynthesising life on them, but Jupiter, Saturn, Neptune and Uranus have gases such as hydrogen, ammonia, methane and carbon dioxide their atmosphere.

The composition of the atmosphere of these planets is probably similar to the first atmosphere that existed after the earth was formed.

All these other planets are believed to have rocky icy cores but their chemical composition is unknown, so although these planets are called 'giant gas planets', that's not the whole story!

10(b) On Mars there appears to be eroded, but now dry, river beds and cliffs showing 'weathered' or 'erosion' features.

Some of the latest observations from Mars that there are huge amounts of water in the north and south polar ice caps.

Mars has a very thin atmosphere of carbon dioxide.

10(c) The Moon

• The moon does NOT have an atmosphere, its mass, and hence its gravity, is too low to hold on to an atmosphere.

• There are no sedimentary rocks on the moon because there is no atmosphere, so there has been no weather to bring about weathering, erosion, transportation, deposition and compression to form sedimentary rocks.

• There will be metamorphic rocks on the moon because there is evidence of volcanic activity and even igneous rocks when heated can re-crystallise to form a 'new' metamorphic rock.

10(d)(i) The surface on Venus is much hotter than the Earth, not only because it is closer to the Sun, but because it has a dense atmosphere of mainly carbon dioxide. This produces a Super-Greenhouse-Effect!

10(d)(ii) The surface on Mars is much colder than Earth, not only because it is further away from the Sun, but because it has very little atmosphere even though its mainly carbon dioxide. This means there is little of the so-called 'Greenhouse-Effect', i.e. little  trapping of re-radiated infrared heat radiation from the surface of Mars. However, there are clear signs that water ran on the surface of Mars at some time and dry river beds and canyons have been photographed as well as extinct volcanoes.

10(e) Pluto is an extremely cold rocky lump with an icy surface of frozen methane and has been demoted to the status of a 'dwarf planet'.

10(f) Mercury, the closest planet to the sun, is a small very hot rocky planet with no atmosphere - its too hot and too small (small gravity) to hold onto an atmosphere. It probably never have had an atmosphere system to create weather systems and so most of its rock is probably igneous.

GCSE level QUIZ and WORKSHEET QUESTION LINKS

INDEX OF EARTH SCIENCE PAGES

foundation-easier multiple choice quiz on Earth Science

higher-harder multiple choice quiz on Earth Science

Five linked Earth Science word-fill worksheets Q1 * Q2 * Q3 * Q4 * Q5

Answers to the five GCSE Earth Science worksheets listed above

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