Light waves are electromagnetic waves that oscillate at a frequency that can be detected by the human eye. Natural light from the Sun is made of waves having a range of different frequencies. Every wave frequency is visible to us like a various colour. Red light, for instance, is caused by waves having a frequency [...]

Each and every day, nuclear reactions at the Sun’s centre create electromagnetic radiation that shoots into space. Light is one type of this radiation, and without the energy it provides most life on Earth would die. Nevertheless, other kinds of electromagnetic radiation are extremely harmful to living organisms.
Electromagnetic radiation is emitted from numerous objects, not [...]

The most recent lumps of rock to become designated moons are the 19th and 20th moons of Saturn. Discovered by the Voyager 2 probe, they do not have official names yet, so are known simply as 1995-S3 and 1995-S4, after the year of their confirmation as moons. As astronomers continue to study information returned from [...]

The moons in the Solar Program vary enormously in size. The biggest are bigger than the planet Pluto; the smallest are kilometre-sized lumps of rock. Moons more than about 300km across are spherical, while smaller moons tend to become irregular and potato-shaped. The larger moons were discovered from Earth. The smaller ones were identified by [...]

Astronomers know there are more than sixty moons within the Solar System and think there may be many more. Most from the known moons orbit the four giant planets: Jupiter, Saturn, Uranus and Neptune. It is no coincidence that these are also the four ringed planets, simply because the lives from the rings and moons [...]

Many ancient civilizations believed light were a gift from the Sun god. If he wasn’t worshipped daily, they believed he would show his wrath by disappearing. Then the Earth’s temperature would drop, rivers and lakes would freeze, and plants and animals would die.
The ancients knew many things about what light is. They realized that it [...]