2. THE UNIVERSE
The Universe is everything we can touch, feel, sense, measure or detect.
It includes living things, planets, stars, galaxies, dust clouds, light, and even time.
Before the birth of the Universe, time, space and matter did not exist.
The Universe contains billions of galaxies,
each containing millions or billions of stars.
3. THE BIG BANG
• Most astronomers believe the Universe began in a Big Bang about 14 billion years ago. At that time,
the entire Universe was inside smaller than a pinhead. It was hotter and denser than anything we
can imagine.
• Then it suddenly exploded. The Universe that we know was born. In a fraction of a second, the
Universe grew from smaller than a single atom to bigger than a galaxy. And it kept on growing at a
fantastic rate. It is still expanding today.
• Over the next three minutes, the temperature dropped below 1 billion degrees Celsius.
• After 300 000 years, the Universe had cooled to about 3000 degrees. Atoms were finally formed!
The Universe filled with clouds of hydrogen and helium gas.
4. The Universe is incredibly huge. It would take a modern
jet fighter more than a million years to reach the
nearest star to the Sun.
Travelling at the speed of light (300,000 km / second),
it would take
100,000 years
to cross our Milky Way galaxy alone.
6. SPACE
• 'Outer space' begins about 100 km above the Earth, where the shell of air
around our planet disappears.
• With no air to send sunlight and have a blue sky, space looks like a black
blanket dotted with stars.
7. Did you know…
In space, no one can hear you scream!
This is because there is no air in space.
Sound cannot travel without air.
Space looks empty but the gaps between the stars and planets
are filled with huge amounts of gas and dust.
9. THE SUN
• The Sun is the star at the center of the Solar System. It is a sphere of
hot plasma.
• It is very important because it gives energy for life on Earth.
• Its diameter is about 1.39 million kilometers, 109 times bigger than Earth,
and its mass is about 330,000 times that of Earth.
• It consists of hydrogen (3/4), helium, oxygen, carbon, neon, and iron.
10. VENUS
Venus is the second planet from the Sun. It
takes 243 days to rotate and goes around in
the opposite direction to most other planets.
It is named after the Roman goddess of love
and beauty.
It is the second-brightest natural object in
the night sky after the Moon, and, rarely, visible
to the naked eye during day.
11. MARS
• Mars is the fourth planet from
the Sun and the second-smallest planet
in the Solar System after Mercury.
• Mars takes its name from the Roman
god of war, and we often call it the "Red
Planet“ . It looks red because there is too
much iron oxide on it.
• Mars has got a thin atmosphere, and it
looks like the Moon and the Earth. It has
got valleys, deserts, and ice on the
poles .
12. THE EARTH
• The Earth is the third planet from the Sun and the
only object in the Universe known to have life.
• The Earth formed over 4 billion years ago. It has a
, the Moon.
• The Earth revolves around the Sun in 365.26
days, and this time is called an Earth year.
• The gravity and the interaction between the Earth
and Moon causes ocean tides, stabilizes the
Earth's orientation on its axis, and gradually slows
its rotation.
• The Earth is a very dense planet and the largest
of the four terrestrial planets.
13. THE MOON
• The Moon orbits planet Earth, being the Earth's
only natural satellite.
• It is the fifth-largest natural satellite in the Solar
System. The Moon is the second-densest
satellite compared to Jupiter's satellite Io,.