The solar system NATURAL SCIENCE TERM 4 GRADE

The solar system NATURAL SCIENCE TERM 4 GRADE 8 CAPS PLATINUM Natural Science

The solar system WHERE IS THE SUN? WHERE IS THE EARTH? WHERE IS THE MOON? Put them in order of size from smallest to biggest. Which one is closest to the Earth? Is the Sun a planet or a star? Does the Sun move around the Earth?

The Sun • The sun is a star. • It is a big ball of burning gas. • It is not the biggest star that exists in the universe. It looks bigger and brighter that other stars because it is much closer to Earth than other stars.

The Sun • In its core, nuclear reactions take place. The atoms of hydrogen gas react with one another to form helium gas. • When this happens, LOTS of energy and heat is released.

Objects around the Sun Solar system = Sun + other objects • Planets • Dwarf planets • Moons • Asteroids • Ice and Dust (Kuiper Belt and Oort Cloud)

Objects around the Sun Planets • In order for an object in space to be a planet, it must: • Travel around the Sun in an orbit • Be almost spherical in shape • Be able to keep its orbital path objects clear of other

Objects around the Sun Planets • Planets have their own special features. The categories are: • Size • Distance from the Sun • Number of moons known • Composition • Surface temperature • Time it takes for one orbit around the Sun

Objects around the Sun Planets • There are 8 planets that orbit the Sun: MERCURY VENUS EARTH JUPITER SATURN URANUS MARS NEPTUNE

Objects around the Sun Planets • Scientists divide the planets into 2 groups: • Inner rocky planets • These are called Terrestrial planets because they are made up of rock. • Outer gas giants • Examples are Mercury, Venus, Earth and Mars

Objects around the Sun Planets • Scientists divide the planets into 2 groups: • Outer gas giants • These are made up of gases and liquids. • Examples: Jupiter, Saturn, Uranus and Neptune.

Objects around the Sun Planets • There are 8 planets that orbit the Sun: Inner rocky MERCURY VENUS EARTH MARS Outer Gas JUPITER SATURN URANUS NEPTUNE

Objects around the Sun Dwarf Planets • This is a planet that is other objects. not able to keep its path clear of

Objects around the Sun Moons • This is a body that revolves around a planet. • They do not have their own source of light. The reflect light from the Sun.

Objects around the Sun Moons • Give the number of moons that each planet has: Earth 1 Mars 2 Venus 0

Objects around the Sun Asteroids • This is one of many rocks found in space mostly between the orbits of Mars and Jupiter. • An asteroid belt is a huge area where lots of rock pieces race around the Sun.

Objects around the Sun Meteoroid • A solid object in space that is smaller than an asteroid. • These mostly come from the asteroid belt.

Objects around the Sun Meteor • This is when a meteoroid enters the Earth’s atmosphere and burns up. • Also known as a “shooting star. ”

Objects around the Sun Meteorite • The remains of meteors that crash into the ground before burning up completely.

Objects around the Sun Comets • This is a body made of frozen gases and bits of rock. • It comes from beyond the furthest planets. • Comets enter the Solar System, travel around the Sun and leave

Objects around the Sun Shape of the solar system • The solar system looks like a flat disc. • The Sun spins at the centre and all the objects orbit around it in the same direction.

Objects around the Sun Gravity • Everything in the solar system is held in place by a force called Gravity. • This is the natural force of every object that attracts other objects to itself.

Objects around the Sun Gravity • The more mass an object has, the stronger its gravitational pull. • The closer the objects are to each other, the stronger the gravitational pull between them.

Objects around the Sun Gravity • Of all the bodies in the Solar System, the Sun has the most mass and therefore the strongest force of gravity. Hence, other planets revolve around the Sun.

Objects around the Sun Kuiper Belt • This is a ring of icy and rocky objects that is very far away from us.

Objects around the Sun Oort Cloud • This consists of lumps of dust and gases and is spherical in shape as it surrounds the Solar system. • Scientists think that comets that occasionally enter our Solar System come from the Oort Cloud

Earth’s position in the Solar System

Earth’s position in the Solar System • Earth is the third planet from the Sun. • It is also the only planet that can support life (as far as we know).

Earth’s position in the Solar System • The conditions that are needed in order to support life are: 1. Temperature 2. Sunlight 3. Water 4. Oxygen

Earth’s position in the Solar System let’s talk about…. TEMPERATURE A planet’s temperature is affected mainly by it’s distance from the Sun and also by it’s atmosphere.

Earth’s position in the Solar System let’s talk about…. TEMPERATURE

Earth’s position in the Solar System let’s talk about…. SUNLIGHT • The Sun releases radiant hea energy (energy ligh in the form of and t t this ) and eventually reaches Earth.

• Earth’s position in the Solar System let’s talk about…. SUNLIGHT This energy enables life to exist on Earth: For example: • Plants need it to make food. • Animals depend on the plants for food. • It heats up parts of the Earth and creates

• Earth’s position in the Solar System let’s talk about…. WATER EXISTS IN ALL 3 STATES ON EARTH AS FOLLOWS: Surface and underground water Water Ice Caps vapour in air Liquid Solid Gas

Earth’s position in the Solar System let’s talk about…. WATER • Water constantly changes between 3 states in the water cycle. • This cycle ensures that the amount of water on Earth stays more or less the same and that there is fresh

Let’s see what you know…. TB pg. 228 2. 3. 1. 6. 4. 5.

Earth’s position in the Solar System let’s talk about…. OXYGEN • Oxygen is essential for life on Earth because it is needed in breathing processes and to release

Earth’s position in the Solar System let’s talk about…. OXYGEN • Early life forms, like bacteria, were most likely the first to start producing oxygen. As more oxygen then became available, it allowed more complex life forms to evolve. • Today oxygen is produced by plants during

Homework TOPIC 11 REVISION PG. 208