chapter 5 our solar system survey of astronomy astro1010-lee.com [email protected]
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Chapter 5Our Solar System
An Inventory of the Solar SystemEarly astronomers knew: Sun, Moon, Stars, Mercury, Venus, Mars, Jupiter, Saturn, comets, and meteors
Now we know: Solar system has one star, eight planets (added Uranus, and Neptune), 135+ moons, asteroids, comets, and meteoroids.
Pluto was added as a Planet then reduced to a Dwarf Planet
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Chapter 5Our Solar System
Planetary PropertiesOrbital period can be observed
Distance from Sun known by Kepler’s laws
Radius known from angular size
Masses from Kepler’s 3rd Law as modified by Newton’
Rotation period from observations
Density can be calculated knowing radius and mass
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Chapter 5Our Solar System
Comparison of the Terrestrial Family of Planets to the Jovian Family of Planets
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Chapter 5Our Solar System
Differences between the terrestrial planets
Atmospheres and surface conditions are very dissimilar
Only Earth has oxygen in atmosphere and liquid water on surface
Earth and Mars rotate at about the same rate; Venus and Mercury are much slower, and Venus rotates in the opposite direction
Earth and Mars have moons; Mercury and Venus don’t
Earth, Mars and Mercury have magnetic fields; Venus does not.
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Chapter 5Our Solar System
Interplanetary Debris
Asteroids and meteoroids are rocky; asteroids are bigger
Asteroid Eros is 34 km long:
Comets are icy, with some rocky parts.
Comet Hale–Bopp
Chapter 17A
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Cloud of gas and dust contracts due to gravity. Conservation of Angular Momentum means it spins faster and faster as it contracts
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Chapter 5Our Solar System
Condensation theory:
Interstellar dust grains help cool the
cloud, and act as condensation nuclei
to produce flakes
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Chapter 5Our Solar System
Local temperature in the condensing cloud determines where various materials condense
Early Spacecraft Exploration of the Solar System
Soviet Venera probes landed on Venus from 1970–1978
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Early Spacecraft Exploration
Pioneer and Voyager flew through the outer solar system. This is Voyager
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Chapter 5Our Solar System
End Chapter 5