GCSE Science Chapter 12 Origin of the Solar

GCSE Science Chapter 12 Origin of the Solar System

GCSE Science Chapter 12 Origin of the Solar System The solar system was formed by a gravitational fall of a cloud of gas made up of hydrogen, helium and dust. Next

Orbit of the Planets 1 GCSE Science Chapter 12 Mercury Earth Venus Mars • The four inner planets are rocky. • They are kept in an orbit around the sun by gravity.

Orbit of the Planets 2 GCSE Science Chapter 12 Jupiter Uranus Saturn Neptune • The other planets are gas giants. • Pluto is no longer considered to be a planet!

GCSE Science Chapter 12 Comets • A comet’s orbit is an ellipse shape. • The comet’s tail always points away from the sun - why?

GCSE Science Chapter 12 MERCURY § No atmosphere. § Closest to the sun. § Daytime temperature 350°C. § Night time temperature 180°C.

GCSE Science Chapter 12 Venus § Thick and dense atmosphere made up of sulphuric acid and carbon dioxide. § Severe greenhouse effect. § No life. § No moon.

EARTH GCSE Science Chapter 12 • Blue planet with clouds. • Oxygen and water available. • Inhabited by life forms.

MARS GCSE Science Chapter 12 § Rocky with red dust on its surface. § May once have had water § No life found here so far.

JUPITER GCSE Science Chapter 12 § The largest planets (all the other planets would fit into this one!). § Atmosphere of liqui hydrogen and helium

SATURN GCSE Science Chapter 12 Rings of small rocks encased in ice.

URANUS GCSE Science Chapter 12 § Pale green colour. § Looks as if it’s lying on its side (it has a horizontal axis).

NEPTUNE GCSE Science Chapter 12 § Similar to Uranus. § Blue in colour.

PLUTO GCSE Science Chapter 12 § Not considered to be a planet any longer. § About 1/5 of the size of the Earth.

Asteroids § § GCSE Science Chapter 12 § There is an asteroid belt between Mars and Jupiter. These are bits of rock of varying sizes. These are affected by the gravitational pull of the planets, and some have even collided with earth!

GCSE Science Chapter 12 Comets § Made up of a mixture of ice and dust. § Come from two places: Oort cloud (beyond the solar system), and the Kuiper belt (beyond Neptune). § They have elliptical orbits. § Tails always point away from the sun and are millions of kilometres long!

GCSE Science Chapter 12 Relative sizes

Data on the Solar System Planet GCSE Science Chapter 12 Mercury Diameter (km) Distance from the Sun (km× 106) Orbit (Years) Average Temperature (°C) 4900 58 0. 24 350 You are not expected to learn this Venus 12000 108 0. 62 450 information, but you will need to use Earth 12800 to draw 150 a conclusion 1. 00 e. g. 15 the data …. . Mars 6800 228 1. 88 -30 Jupiter 143000 780 12. 00 -150 Saturn 120000 1430 29. 00 -180 Uranus 52000 2800 84. 00 -210 Neptune 49000 4500 165. 00 -220 Pluto 3000 5900 248. 00 -230

CONCLUSION: GCSE Science Chapter 12 The average temperature of the planets decreases with their distance from the sun. Venus is an exception due to the greenhouse effect. The change is not constant.

CONCLUSION: GCSE Science Chapter 12 The time it takes for planets to orbit the sun increases with distance. The change is not constant.

GCSE Science Chapter 12 GRAVITY § Gravity is the force that exists between two or more masses. § Gravitational force always attracts mass. § Approximately 1/1, 000 N exists between you and the person next to you (it’s not strong enough to affect us).

Gravity GCSE Science Chapter 12 A The earth has a lot of mass, so its gravitational attraction on our bodies keeps us on the ground.

GCSE Science Chapter 12 GRAVITY § Gravity is the force that keeps the planets in orbit around the sun. § Gravity i the force that keeps the moon (the earth’s natural satellite) in its orbit around the earth. § Gravity is the force that keeps satellites in their orbits around the earth. § Gravity always act on the centre of a mass.

GCSE Science Chapter 12 GRAVITY If it’s possible to fire a gun quickly enough, then the gravitational force that pulls the bullet down towards the centre of the earth, causes it to orbit around the earth.

GRAVITY - SUMMARY GCSE Science Chapter 12 Gravity meter § A small body keeps in orbit around a larger body because of its high mass, and the gravitational force between the two bodies. § The larger the distance between the two bodies, the weaker the gravitational force. § The greater the mass, the greater the gravity.

DISCOVERING NEW PLANETS GCSE Science Chapter 12 The effect of another planet’s gravity § A planet’s orbit is something that can be predicted, but sometimes a planet shows a change in its path. Sometimes, the gravitational pull of another planet affects its path. § We have been able to use this sin our search for new planets. § April 24, 2007 – a planet similar to earth, 20. 5 light years away, was found, with a larger gravity (1. 6 more than earth).