Transcript ppt - Faculty Virginia

Overview of the Solar System
Solar system contents – one star, several planets, lots of debris.
Most of it is the Sun!
99.8% of the mass of the Solar System resides in the Sun.

A hot ball of mostly hydrogen and helium held together by gravity.

In bulk composition it resembles an unbiased scoop of galactic material.
Most of it is the Sun!
99.8% of the mass of the Solar System resides in the Sun.

A hot ball of mostly hydrogen and helium gas held together by gravity.

In bulk composition it resembles an unbiased scoop of galactic material.
3/4 Hydrogen
1/4 Helium
1% other
elements
Eight Major Planets
Maybe one or two more depending on semantics and future
discoveries.
Four Jovian Worlds
Jupiter, Saturn, Uranus and Neptune

“Gasballs” constituting 99.9% of the planetary mass
Four Jovian Worlds
Jupiter, Saturn, Uranus and Neptune
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Hydrogen and helium, under high pressure, become dense
liquids – more appropriately these are spinning liquid droplets.
Four Terrestrial Worlds
Mercury, Venus, Earth, and Mars
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Small rocky/metallic worlds hugging the
Sun with thin or non-existent
atmospheres.
Jovian vs. Terrestrial Characteristics
Terrestrial: Mercury, Venus,
Earth, and Mars
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Small relatively speaking
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Solid rocky cratered surfaces with
significant iron cores
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Three satellites between them all
Jovian vs. Terrestrial Characteristics
Jovian: Jupiter, Saturn, Uranus, Neptune – The “Gas Giants”
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about 10 times bigger than the terrestrial worlds
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Gaseous with no solid surface, resembling the Sun in composition (mainly
Hydrogen and Helium) .
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Clouds of Methane, Water, Ammonia, and other molecules provide an apparent
“surface”

More than one hundred satellites – most made mainly of water/ice.
Jovian vs. Terrestrial Characteristics
Jovian: Interiors of compressed liquified gas
Jovian vs. Terrestrial Characteristics
Jovian: Cloudtop “surfaces”
Jovian vs. Terrestrial Characteristics
Jovian: Many satellites
Jovian vs. Terrestrial Characteristics
Jovian: Icy satellites
Jovian vs. Terrestrial Characteristics
Jovian: Satellites as big as planets, some with atmospheres.
Minor Constituents: Asteroids, Comets, and Dust
Asteroids: Millions of small rocky objects mostly between the
orbits of Mars and Jupiter
Minor Constituents: Asteroids, Comets, and Dust
Asteroids: Millions of small rocky objects mostly between the
orbits of Mars and Jupiter
http://www.daviddarling.info/encyclopedia/A/asteroid.html
Minor Constituents: Asteroids, Comets, and Dust
Asteroids: Millions of small rocky objects mostly between the
orbits of Mars and Jupiter
An Outer Icy Asteroid Belt
Another group of asteroid-sized bodies orbit beyond Neptune in
the “Kuiper Belt”

Pluto is one of the largest of these.
A Cloud of Cometary Nuclei
Trillions of small iceballs, most only a kilometer in size, orbit as
far out as ½ way to the nearest star.

only a small fraction make it into the inner solar system to be heated by
the Sun to become a comet.
A Cloud of Cometary Nuclei
Trillions of small iceballs, most only a kilometer in size, orbit as
far out as ½ way to the nearest star.

only a small fraction make it into the inner solar system to be heated by
the Sun to become a comet.
Interplanetary Dust
The grinding of asteroids and evaporation of comets populates
the inner solar system with fine dust.
http://www.astrophoto.com/images.htm
Interplanetary Dust
The grinding of asteroids and evaporation of comets populates
the inner solar system with fine dust.
Interplanetary Dust
The grinding of asteroids and evaporation of comets populates
the inner solar system with fine dust.
Regular Features of the Solar System
All of the planets orbit the Sun in the same plane
All planetary orbits are nearly circular
All planets orbit the Sun in the same “direction”
Most planets rotate in the same sense as the orbit.
See orbits
Regular Features of the Solar System
The Jovian and Terrestrial planets are well sorted in terms of
distance from the Sun.

rocky worlds close – gaseous/icy worlds far away
Regular Features of the Solar System
All of the planets orbit the Sun in the same plane
All planetary orbits are nearly circular
All planets orbit the Sun in the same “direction”
Most planets rotate in the same sense as the orbit.
See orbits
Regular Features of the Solar System
The Giant Planet satellite systems resemble the Solar System
Regular Features of the Solar System
Exposed solid surfaces are heavily cratered throughout the
Solar System.
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The process was messy and produced lots of leftovers.
Regular Features of the Solar System
Exposed solid surfaces are heavily cratered throughout the
Solar System.

The process was messy and produced lots of leftovers.
Building a Solar System through “Accretion”
These regular features are “fossilized” memory of the conditions
that gave rise to the Solar System.

In sum, they suggest the planets grew within a rotating flattened disk
and, today, their orbits reflect the structure of that disk.