The solar system
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Transcript of The solar system
Which is the biggest planet?
How many planets are there between the Earth and the Sun?
What other elements are there in the Solar System?
How many planets are in The Solar System?
The Solar System consists of the Sun, eight plantes and their moons, comets and asteroids. They are all called celestial bodies.
Everything in the Solar System orbits the Sun.
The Sun is the largest celestial body, It is much bigger than any planet.
It is a yellow star which provides the light and the heat neccesary for life on earth,
It is at the centre of the Solar System.
The Sun rotates on its own invisible axis.
There are eight large celestial bodies called planets.
Each planet rotates on its own invisile axis.
VenusEarth
Each planet also orbits the Sun.
Terrestrial Gas giants
Mercury Jupiter
Venus Saturn
The Earth Uranus
Mars Neptune
They are small and mainly made up of rock They are large and are made up of gases
The Planets are classified into two groups:
This picture shows a moon orbiting a planet. An orbit is the path followed by something that revolves, or goes around something else
Natural Satellites are smaller celestial bodies, such as moons, which orbit their planets.
An asteroid trail movie
In the Solar System there are thousands of tiny, rocky celestial bodies called asteorids.
They have different shapes.
Comets are small celestial bodies made up of ice, dust and rock.
They have bright tails which point away from the Sun. We can only see the tail of a comet when it is close to the Sun.
The Earth revolves around the Sun. Its orbit is an elongated circle, called ellipse.
The Earth take exactly 365 days and 6 hours to complete its orbit. Our “normal” calendar years are only 365 days long.
The Earth is a sphere. It rotates on its own invible axis, which pases through the North and South Poles. It takes 24 hours to complete this rotation.
One half of the Earth is facing the Sun. In this half it is day.
This half is facing away from the Sun. It does not receive sunlight. In this half it is night.
The Earth always rotates in the same direction. Consequently , the Sun always rises in the east and sets in the west.
Sun rise Sunset
North hemisphere
South hemisphere
In geometry it is an exact half of a sphere.
It also refers to half of the Earth
The Earth´s axis is slightly tilted.
This hemisphere is tilyed away from the Sun. It receives less light and heat. It is winter in this hemisphere.
This hemispehere is tilted towards the Sun, It receives more light and heat. It is summer in this hemisphere.
This hemispehere is tilted towards the Sun, It receives more light and heat. It is summer in this hemisphere.
This hemisphere is tilyed away from the Sun. It receives less light and heat. It is winter in this hemisphere.
The Moon is the Earth´s only natural satellite. It takes 27,3 days to orbit the Earth.
The Moon rotates on its axis in the same time it takes the Moon to orbit the Earth. The same side of the moon always faces the Earth.
New Moon
Firts quarter
Full Moon
Last quarter
When we look to the Moon from Earth, its appearance changes throughout the lunar month. These changes in appearance are called lunar phases.
NEW MOON: no part of the Moon is visible because the side of the Moon facing the Earth is not being lit by the Sun.
FIRST QUARTER: one half of the Moon is being lit by direct sunlight. This iluminated half is increasing.
FULL MOON: the side of the Moon facing the Earth is being lit by the Sun.
LAST QUARTER: the other half of the Moon is being lit by direct sunlight. This illuminated hald is decreasing.
MoonEarth
Sun
Sometimes during their orbits, the Moon, the Earth and the Sun align and an eclipse occurs.
During a lunar eclipse, the Earth passes between the Sun and the Moon, and blocks the Sun´s light. The Earth´s shadow moves across the surface of the Moon.
During a solar eclipse the Moon passes between the Earth and the Sun and it blocks the Sun´s light and projects a shadow on the Earth. When the Moon and Sun are in the perfect line it is called total eclipse.
Never look at the Sun during an eclipse without adequate protection. You can look at the Sun without filters only when it is totally eclipsed.
A star is a spherical body which generates light and heat thriugh nuclear reactions. Most stars consist of the gases hydrogen and helium.
Stars have different characteristics:
Colour: Depending on their temperature, stars can be red, orange, yellow, white or blue.
Size: all stars are enormous, but some are larger than others.
Luminosity: this refers to the amount of light from the star which reaches the Earth.
Stars are divided into 88 groups or constellations to make identification easier. The constellations have the names of characters from classicalmythology or the names os animals and objects because of the shapes they form.
The Ursa major, or the Big Bear, can be seen all year.
Orion constellation can only be seen in winter.
Hercules constellation can only be seen in summer.
A nebulae is a cloud of dust and gas. Some nebulae are illuminated by stars near them. New stars are formed in some nebulae.
Galaxies are enormous group os stars, gases and dust.
There are three types:
elliptical
spiral
irregular
Our Solar System is on the edge of galaxy called the Milky Way. All the stars which we can see belong to this galaxy.
