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Explore the fascinating world of asteroids, meteoroids, and comets. Learn about their composition, orbits, and impact on Earth. Discover the difference between a meteoroid, meteor, and meteorite. Witness meteor showers and uncover the mysteries of famous comets like Haley's Comet. This informative guide will take you on a cosmic journey through our celestial neighborhood.
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Asteroids • Asteroids – A rocky lump of frozen gas that can range in size from a few hundred feet to several hundred miles wide. • Matter that is similar in composition to the planets. Sometimes, it’s called a Planetoid. • Orbit in a belt between Mars and Jupiter. • Largest asteroid known: Ceres (1801)
Asteroid Gaspra – photographed by the Galileo spacecraft in 1991.
What prevents the Asteroids in the belt from plunging into the sun and hitting the inner planets in the process? • The Sun’s gravity and Jupiter’s gravity!
Meteoroids • Meteoroids – Small fragments of matter, like rock, stone, and metals (smaller than asteroids) that orbit the sun at a variety of speeds; pieces of planets, moon, or asteroids • Meteor - “shooting star” • This happens when a meteoroid enters Earth’s atmosphere and begins to burn. • Briefly visible • Fireball – Long streaks of bright light created by these racing meteors
Fireball from a meteor in the night sky. • Pennsylvania 1992
Sometimes meteors strike Earth! • Meteorite – a meteor that impacts the ground. • Most meteorites fall into the oceans. • Most meteorites fall to earth as dust, because they burn up in the atmosphere. • “Micrometeorites” strike Earth daily. These can be as small as pebbles. • Size of a mountain every 10,000 years. • Craters are created when large meteorites strike a moon or planet. • 3 km wide in Quebec, Canada
Largest Meteorite to strike US – Oregon 1902 • 1954 – crashed through the living room and injured a woman.
What’s the difference between a meteoroid, meteor, and meteorite? • Meteoroid – still in space • Meteor – enters earth’s atmosphere • Meteorite – meteor that strikes earth because it’s so big it doesn’t burn up. • Seen during a football game. • Pieces of it crashed into the trunk of a parked car.
Meteor Shower • The 1966 Leonids Meteor Shower • Arizona; 2300/minute for 20 minutes
Comets • Comets – lumps of frozen gas and rock that orbit the sun in a highly eccentric way. • A heavenly body that is usually named after its discoverer. • Believed to originate in an Oort cloud. (Huge cloud that is thought to surround our solar system). • Nucleus – the center of a comet. • Coma – large halo of gas and dust that forms around the nucleus of a comet when it gets close to the sun. It actually loses mass as it gets close to the sun.
More about a comet • Comets orbit the sun in an elliptical pattern. • Comets have tails. Their tails are made of frozen gases, cosmic dust, and rocky particles. As a comet travels toward the sun, its head leads the way. But as it travels away, its tail leads the way. This is due to Solar winds. • Haley’s comet – a space curiosity that returns to Earth’s view every 76 years.
Haley’s Comet • It has been spotted for thousands of years. • Sir Edmond Halley – English astronomer (1656-1742)
Can you find Haley’s Comet in the tapestry below dated from 1066 A.D.?