Earth Science Notes
The Solar System
Models of the Solar System
The Earth Centered Model
 Ptolemy was the early proponent
 Idea that the sun, moon, and stars were on _________________ spheres that rotated
around the earth.
 AKA: _________________ model
Sun-Centered model
 Nicholas Copernicus first to come up with the idea
 Idea that the moon ________________around the Earth and the Earth around the sun
 AKA: _________________ Model
 Galileo was the first to prove this idea
– Showed with his telescope that ______________went through phases like our moon
 This must mean that Venus orbits the sun as well
– Apparent changing of Venus’s diameter
Modern Model of Solar System
 Made up of 8 planets (was 9)
– Pluto is now _________________ as a _________________
 Planets have elliptical orbits
– Kelper’s first law of __________________________________
Most of the mass of our solar system is the sun (99%)
Formation of the Solar System
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Ingredients: _________________ and _________________
Large mass of dust and debris started to _________________, forming discs with
really dense centers.
The centers of the disc became so dense and hot (10 million degrees C) that
_________________ _________________ began
– This led to the formation of the sun
Planets formed from the debris that did not get pulled into the center of the growing
disc.
Loose matter _________________ and _________________ together; forming planets
The temperature close to the sun is high so it _________________ elements that had
low boiling points
– That is why the inner 4 planets are solid
– The outer planets are made up of gases like helium, _________________, methane
and _________________.
Planet Formation
 Dust and grains begin to _________________ together. _________________ between
larger and larger objects produce an _________________ -sized body.
 The growing body heats up and begins to melt.
 Dense molten metal particles pool together and sink towards the center of the body.
Lighter silicate liquid, or magma, rises towards the surface, leaving denser solid
minerals in the _________________
 The result: a layered, or _________________, body with core, mantle, and crust.
Other objects in the Solar System
Comets
 Made of ______________, ______________, ______________, and other gases
 Comets in our Solar System
 Halley’s Comet
– 1986 (76 y cyc)
 Comet Hale-Bopp
Meteoroids, Meteors, Meteorites
 Meteoroids - _________________ of rock and debris
 Meteors – meteoroids that enter Earth’s atmosphere and _________________
 Meteorites – meteors that _________________ Earth’s Surface
o Barringer Crater in AZ, approx. 1.2 km (4000 ft) wide.
o On June 30, 1908, a ball of fire exploded about 6 miles (10 kilometers) above the
ground in the sparsely populated region, scientists say. The blast released 15
megatons of energy—about a thousand times that of the atomic bomb dropped on
Hiroshima—and flattened 770 square miles (2,000 square kilometers) of forest.
Asteroids
 Rock _________________ to materials that form the planets (leftovers)
 Most located in a belt between _________________ and _________________
 It is thought at times in the past _________________ may have collided w/ Earth
 It is also thought that the path of an asteroid may cross the path of Earth in the future
– In 2004, a newly discovered 320 m asteroid 99942 Apophis achieved the highest
impact probability of any potentially dangerous object. The probability of collision on
April 13, 2029 is estimated to be as high as 1 in 17
Summary
 Models of the solar system change with new evidence
– Geocentric / heliocentric / modern view
 Formation of the solar system was dependent on gravity
 Sun utilizes nuclear fusion
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More than just the sun and planets in our solar system