Sunday, 29 May 2016

THE EARTH, THE MOON AND THE SUN

1.The Earth
  • The Earth is roughly (approximately) spherical.

Earth's Movement around the Sun

  • ROTATION: The Earth also spins on its own axis once every 24 hours. This causes day and night on Earth. On the part of the Earth that is facing the sun, it is day; on the part of the Earth that is facing away from the sun, it is night.



  • ORBIT / REVOLUTION : The Earth travels around the Sun once every year 365 days and 6 hours ( we've got a Leap-year every four years because of this).




SEASONS: When the Earth orbits the Sun it's a little wonky. Earth's axis is tilted.When the Northern hemisphere is tilted towards the Sun it's Summer and when the Northern hemisphere is tilted away from the Sun is Winter.

2. The moon

The moon is roughly (approximately) spherical and is smaller than the Earth.

The moon travels around the Earth once every 28 days.

We only see the part of the moon that is lit by the Sun. So sometimes we see the whole Moon and sometimes we only see part of the Moon.



3. The sun
  • The sun is a star and gives out heat and light.
  • It is approximately spherical in shape . It's much bigger than the Earth.
  • The Earth is just one of eight planets that travel around the sun. The other planets are called Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune.




4. Eclipses

Solar eclipse


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A Solar Eclipse occurs when the moon goes in front of the sun and blocks most of the sun's light from the earth.
It is dangerous to look at a solar eclipse directly, even if you have sun glasses or smoked glass.



Lunar eclipse

A lunar eclipse occurs when the moon passes through the shadow of the earth. It is not dangerous at all to look at a lunar eclipse because the moon does not make its own light.



IN SPACE: SOLAR SYSTEM




DEFINITION
The Solar System is made up of the Sun, the planets, their moons, asteroids and comets.

WHAT TO SEE

The Sun
The Sun is a star that lives at the centre of the Solar System. Its huge gravity holds the planets in place.
The planets
The planets all revolve around the Sun. There are eight in total - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Moons
Moons rotate around their parent planet. Earth has one moon, but some planets have over 50. Only Mercury and Venus do not have any moons.
Asteroids
Asteroids are rocky bits of runs up to 1,000km (620 miles) across. Most live in the asteroid belt between Mars and Jupiter. They are the remnants from early planets that collided and were torn apart.
Comets
Comets are dirty snowballs of ice and dust that revolve around the Sun in long orbits. When they approach the Sun they heat up, leaving a trail of gas behind them, which looks like a tail.
Recent comets to fly-by the Sun include Halley, Hale-Bopp and Ikeya-Zhang.
THE PLANETS

  • The Rocky or Terrestial planets

The four planets closest to the Sun are:




  • Mercury
  • Venus
  • Earth
  • Mars

  • These are called the 'rocky' or 'terrestrial' planets. They are small by planetary standards and made of similar materials to the Earth.
    • The Gas Giants or Jovial planets
    The next four planets are:




  • Jupiter
  • Saturn
  • Uranus
  • Neptune

  • They are known as the 'gas giants'. They all have rings and lots of moons. The gas giants are made up mostly of hydrogen, helium, frozen water, ammonia, methane, and carbon monoxide.
    The Dwarf Planets
    The International Astronomical Union redefined the term planet in August 2006, so Pluto is now classified as a dwarf planet. There are two other dwarf planets in the solar system, Ceres and Eris.