UNIT 5: THE UNIVERSECEIP. Tomás Romojaro

Teacher: Daniela A. Ayala M.

January 2011.5th grade of P.E

THE SOLAR SYSTEM

• The Solar System consists of the Sun, eight planets and their moons, comets and asteroids.

• They are all called celestial bodies.

• Everything in the Solar System orbits the Sun.

THE SUN

• The Sun is the largest celestial body. It is much bigger than any planet. It is at the centre of the Solar System.

• The Sun is an enormous yellow star which provides the light and heat necessary for life on Earth.

• The Sun rotates on its own invisible axis.

PLANETS AND SATELLITES

• There are eight large celestial bodies called planets.

• Each planet rotates on its own invisible axis.

• Each planet also orbits the Sun. The planets can be classified into two groups: terrestrials and gas giants.

PLANETS & SATELLITES

• Mercury, Venus, the Earth and Mars are the terrestrial planets. They

are small, and mainly made up of rock.

• Jupiter, Saturn, Uranus and Neptune are called gas giants because they are large and are made up of gases.

• Natural satellites are smaller celestial bodies, such as moons, which orbit their planets.

ASTEROIDS AND COMETS

• In the Solar System, there are thousandsof tiny, rocky celestial bodies called asteroids.

• 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 MOVEMENT OF THE EARTH

• The Earth revolves around the Sun.

• Its orbit is an elongated circle,called an ellipse.

• The Earth takes exactly 365 days and six hours to complete its orbit. Our ‘normal’calendar years are only 365 days long.

THE EARTH

THE ROTATION OF THE EARTH THE SEASONS…

THE MOON AND ECLIPSES

The movement of the moon• 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.

A lunar eclipse : The Earth blocks sunlight from the Moon.

LUNAR PHASES

• When we look at the Moon from Earth, its appearance changes throughout the lunar month.

• These changes in appearance are called lunar phases.• Each lunar phase depends on the Moon’s position in relation to

both the Earth and the Sun.• 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 illuminated 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 half is decreasing.

ECLIPSES

• 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, blocks the Sun’s light, and projects a shadow on the Earth. When the Moon and Sun are in a perfect line, it is called a total eclipse.

STARS,CONSTELLATIONS AND GALAXIES

• STARSA star is a spherical body which generates light and heat

through 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 starwhich reaches the Earth.

CONSTELLATIONS

• Stars are divided into eighty-eight groups or constellations to make identification easier. The constellations have the names of characters from classical mythology or the names of animals and objects because of the shapes they form.

• Some constellations, such as Ursa Major, can be seen all year.

• However, Orion, for example, can only be seen in winter, and Hercules can only be seen in summer.

EXAMPLES OF CONSTELLATIONS

URSA MAJOR ORION

NEBULAE AND GALAXIES

• A nebula 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 groups of stars, gases and dust.

• There are three types: elliptical, spiral and irregular.

• Our Solar System is on the edge of a galaxy called the Milky Way.

• All the stars which we can see belong to this galaxy.

Horse Nebulae & Andromeda Galaxy