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Galaxies and other objects in space. Galaxies. Countless other galaxies exist They may be separated by million of miles-sometimes millions of light-years Galaxies are grouped in clusters Milky Way belongs to a cluster known as the Local Group In the local group there are 45 other galaxies.
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Galaxies • Countless other galaxies exist • They may be separated by million of miles-sometimes millions of light-years • Galaxies are grouped in clusters • Milky Way belongs to a cluster known as the Local Group • In the local group there are 45 other galaxies
Spiral galaxy Barred Spiral Galaxy- There is a Large bar or what appears to be a Straight line of stars that the arms Spiral outwards from Normal Spiral Galaxy The Arms start from a central point And swirl outward
Elliptical Galaxy • May have a many millions to trillions of stars • May have resulted from 2 galaxies colliding • May make up 10-15 % of all galaxies • Closest elliptical galaxy to us is Maffei
Irregular Galaxies • May make up about 25 % of all known galaxies • May have resulted from the collision of spiral and elliptical galaxies • Famous- clouds of Magellan
Other Space objects • All orbit the Sun • Comets • Asteroids • Meteors
Comets • Made of dust, rock particles, mixed with ice, methane and ammonia • Some famous ones include: • Halley’s Comet • Comet Hale Bopp
Halley’s Comet • Named for Edward Halley • Sighted every about 76 years • Last sighting 1986 • The orbit takes 76 years so that is why we only see them every 76 years
Hale Bopp • Named for two amateur astronomers in 1995 • Came closest to the Sun and Earth in March of 1997 • We were able to view its orbit for 18 months
Asteroids • “planet like” • Orbit the sun • Highest concentration found in the Asteroid belt between Mars and Jupiter • Asteroid impact has been credited with the death of the dinosaurs
Meteors and name changes • Thermosphere- meteoroid • Mesosphere- meteor • If it survives to reach Earth- that is- it does not burn up then it is a meteorite • Meteorites are unique particles of rocks, nickel-iron metal and mixtures of the two that come from outer space and reach the earth's surface. They may have traveled from the distant reaches of the solar system or even beyond.
Famous Meteors One huge meteor hit near Flagstaff, Arizona
Meteor Showers • Named usually after the constellation they are from • A celestial event in which a large number of Meteroids are observed reaching Earth’s atmosphere Do occur at regular intervals through out the year