Download Diapositiva 1 - La Escuelona

•The Solar System
•The seasons
•The Sun
•The movement of the Moon
•Planets and satellites
•Lunar phases
•Asteroids
•Eclipses
•Comets
•Stars
•Movement of the Earth •Constellations
•The rotation of the Earth •Nebulae
•Galaxies
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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 is the largest celestial
body. It is much bigger any
planet. It is at the center
of the Solar System.
The Sun is an enormous
yellow star witch provides
the light and heat necessary
for life on Earth. The Sun
rotates on its own invisible axis.
• 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:
– Terrestial and Gas Gigant.
Mercury, Venus, the Earth and Mars
are terrestial planets. The are small,
and mainly made up of rock.
Jupiter, Saturn, Uranus and Neptune
are called gas giants because the are
large and are made up of gases.
Natural satellites: are smaller celectial
bodies, such as moons, which orbit
their planet.
Comets are small celestial bodies
made up of ice. 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 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 is a sphere.It rotates on its own
invisible axis, wich passes throught the
North and South Poles.
It takes twenty- four hours to complete this
rotation.
At any time, one half of the Earth is facing
the Sun. In that half, it is day. The other
facing away from the Sun. It does not
receive sunlight.
The Earth always
rotates in the
same direction.
Consequently, the
Sun always rises in
the east and sets
in the west.
The Earth’s axis is slightly tilted. At
any time, one hemisphere is tilted
to wards the sun, and receives
more light and heat.
It is summer in this hemisphere. The
other hemisphere is tilted
The Moon is the Earth’s only natural satellite.
It take 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.
Den 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 it by direct sunlight.
This luminated half is decreasing.
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.
A stars is a spherical body wich
generates light and heat though
nuclear reactions. Most stars consist of
the gases hydrogen and helium. Stars
have different characteristics.
Stars are divided into eightyeight groups or constellations to
make identification easier. The
constellations have the names of
characters from classical
mythology or the names of
animalsand objects because of the
they form.
Colour: depending on their
temperature, stars can be red,
orange, yellow, white or blue.
Size: all stars are enormous,
but some are largest than others.
Luminosity: this refers to the
amount of light from the stars
wich reaches the Earth.
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.
A nebula is
a cloud of dust
and gas. Some
nebulae are
illuminated by
stars near
Galaxies are enormours 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 wich we can see belong
to this .