The wavelength of a wave is the distance between a point on one wave and the same point on the next wave. It is often easiest to measure this from the crest of one wave to the crest of the next wave, but it doesn't matter where as long as it is the same point in each wave.he wavelength of a wave is the distance between a point on one wave and the same point on the next wave. It is often easiest to measure this from the crest of one wave to the crest of the next wave, but it doesn't matter where as long as it is the same point in each wave.
The four planets closest to the Sun are largely made up of rock, like the Earth, and are called the terrestrial (Earth-like) planets. The next four planets are much larger and made mainly from hydrogen and helium. They are often called gas giants. Pluto is different still, a deep-frozen world of rock and ice.LANETS. A planet is a world that orbits a star. There are nine planets circling around the SunâMercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. They take different amounts of time to orbit the Sun, from only 88 days for Mercury to nearly 250 years for Pluto.
The Earth is made out of many things. Deep inside Earth, near its center, lies Earth's core which is mostly made up of nickel and iron. Above the core is Earth's mantle, which is made up of rock containing silicon, iron, magnesium, aluminum, oxygen and other minerals.