The Earth is a rocky planet with a solid crust and oxygen in its atmosphere.
Lunar eclipses occur when the Moon passes through the shadow cone of Earth
The huge dam built on the Colorado river in the US was named after a former American President.
Jupiter is the largest planet of the Solar System, it has two and a half times the mass of all the other planets combined.
Venus is the 2nd planet from the Sun, the brightest object on the night sky (after the Moon).
When the Sun, Earth, and the Moon are arranged in a straight line, the Moon can partially or completely obscure the Sun.
Saturn is the second largest planet in the Solar System, easily recognisable by its rings.
Dry land on the surface of Earth is divided into continents which are separated by oceans.
The rise and drop of sea levels caused by the gravitational force of the Moon.
Machines converting the energy of flowing or falling water into useful forms of power were already in use in the Middle Ages.
Lateral compressive forces cause rocks to form folds. This is how fold mountains are formed.
Water on Earth is in a continuous state of change. The water cycle includes processes such as evaporation, precipitation, melting and freezing.
The device that transmits human voice as electrical signals was invented by Bell in 1876.
The American inventor presented his invention revolutionising telecommunication at New York University in 1837.
One of the most modern means of transport is the Maglev, capable of travelling at speeds of over 400 km/h.
Typical settlements of the Norsemen were not only established in Scandinavia, they appeared on distant areas as well.
The atomic bomb is one of the most destructive weapons in human history.
The army of Alexander the Great successfully deployed siege towers in its attacks against fortifications.
This animation demonstrates the structure of nitrogen molecules, with one sigma and two pi bonds holding the atoms together.
A series of fortifications built to prevent incursions from northern nomadic groups.
The excellent road and aqueduct system covering the whole empire reflects well the development of the Roman civilisation.
The largest bronze-age building complex of ancient Crete was probably the centre of Minoan civilisation.