Download 14.2 The Solar System Solar System: made of 9 planets and

14.2 The Solar System
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Solar System: made of 9 planets and numerous other objects that orbit the sun
Astronomical Unit: 150 million km, which is the average distance from Earth to the sun, it is
abbreviated AU, if something is 3 AU from Earth then it is 3 times as far away as Earth is from
sun
Comets: dust and frozen gases
Outer Planets
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Huge balls of gas, may have solid core, lots of rings, outer rings of dust and ice
Neptune
o Atmosphere of methane which gives the blue-green color
Uranus
o Axis tilted almost even with plane of its orbit (12 o’clock hand tilted to nearly 3)
Saturn
o Several broad rings made of hundreds of smaller rings made of ice and rock
Jupiter
o Largest planet, Great Red Spot is a huge red whirlwind rotating slowly around middle of
planet, 28 moons, Io moon has more active volcanoes than anywhere else in solar
system
Asteroid Belt
o Between Jupiter and Mars
o Asteroids are pieces of rock made of minerals similar to planet materials
o The asteroids may have become planets if Jupiter’s gravity didn’t keep planets from
forming in that area
Inner Planets
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Solid and rocky
Mars
o Devices on surface left from spacecraft
o Seasons, polar ice caps
o Signs that there was once liquid water
o Red due to iron oxide
Earth
o Surface temp allows water to exist as solid, liquid, gas
o Atmosphere works like a screen to keep ultraviolet rays from reaching surface
o Life thrives
Venus
o Surrounded by thick clouds, can barely see the surface
o Clouds trap energy that reaches planets surface which causes temperatures to reach
470°C (hot enough to bake a clay pot)
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Mercury
o Closest to sun
o Surface heavily scarred with craters left by meteorites which are chunks of rock that fall
from the sky when asteroids break up
Extra definitions that pop up in this section but aren’t in the book…
Asteroid:
A relatively small, inactive body, composed of rock, carbon or metal, which is
orbiting the Sun.
Comet:
A relatively small, sometimes active object, which is composed of dirt and ices.
Comets are characterised by dust and gas tails when in proximity to the Sun.
Far from the Sun it is difficult to distinguish an asteroid from a comet.
Meteoroid: A small particle from an asteroid or comet orbiting he Sun.
Meteor:
A meteoroid that is observed as it burns up in the Earth's atmosphere - a
shooting star.
Meteorite: A meteoroid that survives its passage through the Earth's atmosphere and
impacts the Earth's surface.