Asteroids, comets and meteors
These three short online lessons discuss asteroids, comets and meteors.
These three short online lessons discuss asteroids, comets and meteors.
The Earth behaves like a giant bar magnet and as such there is a magnetic field present around it. The Earth’s magnetic field is thought to be caused by flowing liquid metals in the outer core of the planet which causes electric currents and a magnetic field.
Other objects in the solar system are discussed in this online textbook viz. asteroids, meteorites, comets and dwarf planets.
This 32 minute long YouTube video investigates the water contamination problems in Tanzania, with specific focus on Dar Es Salaam.
This 11 minute long YouTube video describes the various causes and types of water pollutants.
This YouTube video investigates what water pollution is and some examples and effects of water pollution.