Comets, Asteroids, and Meteoroids. 1801 Year Giuseppe Piazzi discovered the first asteroid, Ceres.
Earth and Space Our Solar System Our solar system is made up of: Sun Eight planets Their moons...
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Transcript of Earth and Space Our Solar System Our solar system is made up of: Sun Eight planets Their moons...
Earth and Space
Our Solar SystemOur solar system is made
up of: Sun Eight planets Their moons Asteroids Comets Meteoroids
Inner PlanetsThe inner four rocky
planets at the center of the solar system are:
Mercury Venus Earth Mars
Mercury
Planet nearest the sun Second smallest planet Covered with craters Has no moons or rings About size of Earth’s moon
Venus
Sister planet to Earth Has no moons or rings Hot, thick atmosphere Brightest object in sky besides
sun and moon (looks like bright star)
Covered with craters, volcanoes, and mountains
Earth
Third planet from sun Only planet known to have life
and liquid water Atmosphere composed of
composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).
Mars
Fourth planet from sun Appears as bright reddish
color in the night sky Surface features volcanoes
and huge dust storms Has 2 moons: Phobos and
Deimos
Outer Planets
The outer planets composed of gas are :
Jupiter Saturn Uranus Neptune
Pluto
Dwarf Planet Never visited by
spacecraft Orbits very slowly
Asteroids
Small bodies Believed to be left
over from the beginning of the solar system billions of years ago
100,000 asteroids lie in belt between Mars and Jupiter
Largest asteroids have been given names
Comets
Small icy bodies Travel past the Sun Give off gas and
dust as they pass by
Meteoroids Meteoroid: A small particle from
a comet or asteroid orbiting the Sun.
Meteor: The light phenomena which results when a meteoroid enters the Earth's atmosphere and vaporizes; a shooting star.
Meteorite: A meteoroid that survives its passage through the Earth's atmosphere and lands upon the Earth's surface.
RotationRotation versus versus RevolutionRevolution
RotationRotation is the turning of a body about an axis. The earth rotates once every 24
hours. RevolutionRevolution is the motion of one
body around another. The earth revolves around the
sun once every 364 ¼ days.
Why Do We Have Why Do We Have Seasons?Seasons?
The tilt of the Earth’s axistilt of the Earth’s axis and the revolution around the Sunrevolution around the Sun cause the Earth to have seasons.
Combined Effects of Tilt and Combined Effects of Tilt and RevolutionRevolution
Earth’s Seasons - YearEarth’s Seasons - Year
Why Does The Moon Have Phases?
Phases of the moon are determined by: The relative positions of the
earth, moon and sun. Revolution of moon around the
earth. Your position on the earth.
Instruments and technology used in astronomy
Instruments and technology used in astronomy
Refracting telescope: collects & amplifies light using lenses
Reflecting telescope: collects & amplifies light using mirrors
Binoculars: uses two refracting telescopes to observe 3D objects
Radio telescope: collects & amplifies radio waves emitted by celestial bodies
Radar: measures the distance between the Earth and celestial bodies
Observatory: building that provides the best possible conditions to observe the universe
Satellite: object place around a celestial body to collect/transmit data
Instruments and technology used in astronomy
Space probe: Unmanned spacecraft launched into space to explore celestial bodies
Space rocket: Unmanned spacecraft launched into space, with only one salvageable section
Space shuttle: A salvageable spacecraft launched into space capable of returning to Earth
Space station: A facility place in orbit around the Earth (or other celestial body) that is designed for habitation and to carry out various missions
Measurements in astronomy
AU: Astronomical unit = 150 million km
Distance between the Earth and the Sun
Light year: 9 500 billion km
Pluto (not a planet)
The 2006 debate surrounding Pluto and what constitutes a planet led to Ceres being considered for reclassification as a planet.
A proposal before the International Astronomical Union for the definition of a planet would have defined a planet as "a celestial body that
(a) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and
(b) is in orbit around a star, and is neither a star nor a satellite of a planet"
Ceres (not a planet)
However, and on 24 August 2006 a modified definition was adopted, carrying the additional requirement that a planet must have "cleared the neighborhood around its orbit".
By this definition, Ceres is not a planet because it does not dominate its orbit, sharing it as it does with the thousands of other asteroids in the asteroid belt and constituting only about a third of the mass of the belt. Bodies that met the first proposed definition but not the second, such as Ceres, were instead classified as dwarf planets.
Solar system
A solar system refers to a star and all the objects that travel in orbit around it. Our solar system consists of the sun - our star - eight planets and their natural satellites (such as our moon); dwarf planets; asteroids and comets. Our solar system is located in an outward spiral of the Milky Way galaxy.
Solar system
Galaxy
a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
ICW/Homework
P.293 #1,2,5,6,7 P.294 #10,11,18 P.295 #22,25