Let's prepare our Science Test

What is the he Universe?

The Universe is everything and contains everything.

Galaxies, Stars and nebulae.

• Galaxies are enomous groups of star, gases and dust. There are three types of galaxies according to their shapes: elliptical, spiral and irregular. Our galaxy is called: the Milky Way.
• Constellations are groups of stars.
• Stars are enomous spheres in which nuclear fusion takes place. The emit light and heat.
• Nebulae are gas clouds which reflect the light emitted by the stars around them.

The Solar System.

The Solar System is made up of the sun and the different celestial bodies that revolve around it.

• The Sun is a yellow star which generates light and heat.
• Planets are large celestial bodies which orbit the Sun. The interior planets are: Mercury, Venus, the Earth and Mars. The exterior planets are: Jupiter, Saturn, Uranus and Neptune.
• Satellites are smaller celetsial boides that orbit a planet.
• Asteroids are rocky celestial bodies, smaller than planets which revolve around the Sun.
• Comets are small celestial bodies made of ice, dust and gases which revolve around the Sun.

The Earth and the Moon.

• The rotation of the Earth: the Earth rotates on an axix which passes through both poles. It takes one day to spin around. The rotation of the Earth causes night and day.
• The movement of the Earth around the Sun: the Earth revolves around the Sun. It takes one year for the Earth to complete its orbit around the Sun. The Seasons are the result of the Earth’s tilted axis and its orbit around the Sun.
• The moon takes around 28 days to orbit the Earth.

1. New moon occurs when the Moon is between the Sun and the Earth.
2. First quarter occurs when half of one side receives sunlight.
3. Full moon occurs when the Earth is between the Sun and the Moon.
4. Last quarter occurs when the side of the Moon which faces the Sun is iluminated.