![]() ![]() Meteorites are extremely important to science, as they help us to better understand the origins and composition of the Solar System. The largest known meteorite weighs about 60 tonnes and still sits where it fell, at Hoba, Namibia. Many fall in rugged, inaccessible landscapes and have a poor chance of being located. About 500 meteorites of reasonable size would hit the Earth's surface every year, of which 150 would fall on dry land, and less than 10 would actually be found. Meteorites are named after the locality where they have fallen (town, county, property, river, valley, mountain etc.).Ībout 500 tonnes of meteoritic debris falls to Earth every day, much of it as fine cosmic dust and micrometeorites that fall into the sea. A famous Australian meteorite fall occurred on 28 September 1969 at Murchison, near Shepparton, Victoria. Meteorites which are found after their fireball was witnessed are called 'falls', but if found accidentally long after their arrival they are called 'finds'. Meteorites range in size from pea-sized pieces up to large masses many tonnes in weight. Most are heated for less than 10 seconds while they fall. They can travel at very high speeds, typically from about 5 km - 70 km per second, the fastest ones (over 30 km per second) can be destroyed on impact with the atmosphere. Large meteoroids can form brightly glowing fireballs (bolides) seen clearly in daylight, accompanied by spectacular light and sound effects. They sometimes break up into several pieces while still in flight or when they hit the Earth. Meteoroids that survive their journey through our atmosphere land on the Earth's surface as meteorites. These constellations are much further away than the showers themselves. They are given the name of the constellation which forms their backdrop (e.g. Meteors tend to arrive in 'showers' of many individual meteors at definite times throughout the year. These brief, bright streaks of light are sometimes called 'shooting stars'. The trail of glowing, electrically-charged gases that surrounds and streams away from the meteoroid is called a meteor. When heated to incandescence by friction with air in our atmosphere, they burn up completely at heights of about 80 km - 130 km. The small particles which become meteors typically range from the size of a grain of sand up to the size of a pea. Tiny dust particles get rid of heat as quickly as it is applied, so do not burn up and fall gently on the Earth's surface. Very small meteoroids may remain intact or melt to form glassy droplets which rain down on Earth's surface as micrometeorites. meteorites: larger meteoroids survive their fiery ordeal and land on the Earth's surface.meteors: the initial solid particle (meteoroid) can be too small to survive its flight through Earth's atmosphere and burns up completely when heated by friction with air, to give a momentary streak of light.What is the main difference between meteors and meteorites? Rarely, meteoroids may come from the Moon, Mars or comets. Bodies within this belt range from dust particles up to small planetoids (asteroids) such as Vesta (525 km in diameter). ![]() Most come from the asteroid belt lying between the orbits of Mars and Jupiter, about 400 million kilometres from the Sun. Meteoroids, which are solid pieces of extraterrestrial metal or rock debris, can be knocked out of their orbits in outer space and be captured by Earth's gravity. ![]()
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