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Space Science
Space Science
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Space science is the study of the
structure, components, and
characteristics of the universe.
Space Science
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The major fields of study are classified
according to specific topics.
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astronomy: study of celestial objects,
including stars, galaxies, and planets.
astrophysics: study of the physics and
physical properties of the universe.
exobiology: search for and study of
extraterrestrial life.
planetary science: study of planets.
Space Science
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Universe: Started with a “BIG BANG”:
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explosion of a single atom (primordial atom)
created space, time, and all matter.
occurred less than 14 billion years ago.
cause and what existed/happened beforehand is unknown.
celestial objects still moving away from each
other.
10,000 galaxies
in the center of
the universe.
Photographed
by the Hubble
telescope.
Space Science
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STARS:
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Balls of glowing gas that create energy
through nuclear fusion.
Classified according to color and temperature.
Space Science
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GALAXIES:
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Large collection of matter held together by
gravitational attraction.
Classified by shape: spiral, elliptical, irregular.
Our Milky Way Galaxy is spiral Galaxy.
Spiral Galaxy
Spiral Galaxy
Spiral Galaxy
Elliptical Galaxy
Irregular Galaxy
Colliding Spiral Galaxy
Space Science
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Solar System:
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The solar system consists of many objects in
predictable orbit around the sun.
Orbits are predictable because the sun’s
gravity keeps the planets, asteroids, and
comets in a regular orbits
Most orbits are ellipses (ovals), rather than
perfect circles.
Planets to scale view
Diagram of the solar orbits
Space Science
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Planets:
usually categorized by composition or size.
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Terrestrial planets (Mercury, Venus, Earth, Mars):
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have a solid surface made of rock and metal.
have a slow rotation, high density, and few satellites.
are also called small planets, with diameters less than
13,000 km.
Jovian planets (Jupiter, Saturn, Uranus, Neptune):
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are composed of gas and liquid such as hydrogen and
helium.
have a rapid rotation, low density, and many satellites.
are also called giant planets.
Terrestrial planets
Jovian planets
The Sun
Space Science
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Sun
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Size (diameter)
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Length of rotation
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25 Earth days
Temperature at surface
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865,000 miles
almost 10 times larger than Jupiter
9,900°F
temperature of core is
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almost 281,000,000°F
Space Science
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Sun
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Composition
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70% hydrogen, 28% helium, and 2% other metals
Additional Knowledge
star with average size, brightness, and intensity
 classified as a yellow dwarf
 sun contains more than 99.8% of the total mass of
the solar system
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The Planets of our Solar system
Space Science
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Mercury
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Size (diameter)
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Distance from sun
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88 Earth days
Length of rotation
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36 million miles
Length of orbit
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3,030 miles
58.6 Earth days
Temperature at surface
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-292°F to 800°F
Space Science
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Mercury
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Surface features
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Atmosphere
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very thin
First visited by spacecraft
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rocky and heavily cratered
Mariner l0 in 1974-1975
Additional Knowledge
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closest planet to the sun
has a highly eccentric orbit
Space Science
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Venus
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Size (diameter)
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Distance from sun
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224.7 Earth days
Length of rotation
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67 million miles
Length of orbit
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7,520 miles
243.2 Earth days
Temperature at surface
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870°F
Space Science
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Venus
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Surface features
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Atmosphere
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very thick cloud layer of sulfuric acid in a carbon dioxide
atmosphere. The dense clouds prevent even the most
powerful telescopes from seeing surface.
First visited by spacecraft
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flat, volcanic plains and shallow craters
Mariner 2 in 1962
Additional Knowledge
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has most nearly circular orbit of any planet
roughly the same size as Earth.
one Venus day lasts longer than Venus year
Space Science
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Earth
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Satellites
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Size (diameter)
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93 million miles
Length of orbit
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7,930 miles
Distance from sun
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1 the Moon
365.25 days
Length of rotation
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23 hours, 56 minutes
Space Science
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Earth
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Temperature at surface
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Surface features
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-95°F to 130°F
71% covered with water
Atmosphere
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77% nitrogen, 21% oxygen, and traces of argon,
carbon dioxide, and water
Space Science
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Earth
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Additional Knowledge
oldest known fossils of living organisms are 3.9
billion years old
 Only known planet with liquid water on surface
 light from sun takes about eight minutes to reach
Earth
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Space Science
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Mars
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Satellites
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Size (diameter)
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687 Earth days
Length of rotation
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141 million miles
Length of orbit
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4,220 miles
Distance from sun
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2 Moons
24 hours, 37 minutes (Earth time)
Temperature at surface
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-184°F to 77°F
Space Science
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Mars
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Surface features
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Atmosphere
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very thin
composed mostly of carbon dioxide
First visited by spacecraft
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red dust covering a rocky desert environment
craters, canyons, volcanoes, polar ice caps
Mariner 4 in 1965
Additional Knowledge
easily visible from Earth with the unaided eye
surface area equivalent to Earth’s land surface area
Space Science
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Jupiter
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Satellites
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Size (diameter)
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11.86 Earth years
Length of rotation
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484 million miles
Length of orbit
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89,350 miles
Distance from sun
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63 known
9 hours, 55 minutes (Earth time)
Temperature at cloud tops
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-238°F
Space Science
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Jupiter
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Composition
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First visited by spacecraft
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no solid surface
90% hydrogen and 10% helium
increasing density condenses gas to liquid and metal in the
core
Pioneer l0 in 1973
Additional Knowledge
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largest planet
Great Red Spot is big enough to hold two Earths
more than twice as massive as all other planets combined
Space Science
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Saturn
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Satellites
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Size (diameter)
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29.4 Earth years
Length of rotation
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886 million miles
Length of orbit
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74,900 miles
Distance from sun
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60 known
10 hours, 40 minutes (Earth time)
Temperature at cloud tops
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292°F
Space Science
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Saturn
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Composition
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First visited by spacecraft
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no solid surface
75% hydrogen, 25% helium
rings composed small particles, primarily water ice.
Pioneer 11in 1979
Additional Knowledge
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Least dense of all planets
most prominent and easily visible rings of any giant planet
rings are less than 1 km thick
has the strongest winds in the solar system, measured at
over 1,100 mph at the equator
Space Science
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Uranus
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Satellites
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Size (diameter)
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1 .785 billion miles
Length of orbit
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31,765 miles
Distance from sun
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27 known
also has rings
83.8 Earth years
Length of rotation
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17 hours, 14 minutes (Earth time)
Space Science
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Uranus
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Temperature at cloud tops
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Composition
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no solid surface
consists of hydrogen, helium, and methane
First visited by spacecraft
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-345°F
Voyager 2 in 1986 (only visit)
Additional Knowledge
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not visible to the unaided eye
Space Science
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Neptune
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Satellites
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Size (diameter)
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163.7 Earth years
Length of rotation
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2.795 billion miles
Length of orbit
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30,775 miles
Distance from sun
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13 known
16 hours, 7 minutes (Earth time)
Temperature at cloud tops
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-346°F
Space Science
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Neptune
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Composition
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First visited by spacecraft
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no solid surface
consists of hydrogen, helium, and methane
Voyager 2 in 1986 (only visit)
Additional Knowledge
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not visible to the unaided eye
atmosphere makes the planet appear blue
has very faint and thin rings
Comets and Meteors
Comets
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Comets are a mixture of ices (both water
and frozen gases) and dust that did not
get incorporated into planets when the
solar system formed.
Comets are invisible except when they are
near the Sun.
Comets
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When they are near the Sun and active, comets
have several distinct parts:
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Nucleus: relatively solid and stable, mostly ice and
gas with a small amount of dust and other solids.
Coma: dense cloud of water, carbon dioxide and
other neutral gases sublimed from the nucleus and
surrounded by a huge (millions of km in diameter) but
very sparse envelope of hydrogen.
Continued…Next Slide.
Comets
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Dust and Ion tail: up to 10 million km long composed
of smoke-sized dust particles driven off the nucleus
by escaping gases; this is the easiest part of a comet
to see with the unaided eye. Ions are as much as
several hundred million km long composed of plasma.
Comets
Comet West
Comet Hally
Comet Hale-Bopp
Comet Hyakutake