Download Introduction to the Solar System

#5 Introduction to the
Solar System
Just one star
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Not studying galaxies (billions of stars)
or star clusters (millions of stars) yet,
only our own solar system.
Solar means “sun” so
solar system = sun system
Sun is a star, and is our only one!
How to measure something so large?
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The distance between stars (and galaxies)
is HUGE so we measure it in light years.
Light Years is the distance light will
travel in a year
**very important**: a light year is not a
time, but a distance!
Astronomical Units
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Planets in our solar system are closer
together, so we can use AU
(Astronomical units)
1 AU=Average distance between
the Earth and the sun (lazy
scientists)
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Ex) Mercury is closer to sun (.39 AU)
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Ex) Pluto is further from sun (39.5 AU)
The Planets
Now have 8 planets orbiting the Sun
 Orbits are elliptical
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• An ellipse is a shape that can be
thought of as a "stretched out" circle or
an oval
Two major planet groups
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The planets are divided into two major
groups
• 1. Terrestrial Planets (Inner Planets)
• 2. Gas Giants (Outer Planets)
These two groups are separated in the
middle by the asteroid belt
Gas Giants
Asteroid Belt
Inner Planets
Terrestrial Planets

Inner Planets (closest to the sun)
• Mercury, Venus, Earth, Mars
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“Terrestrial” = “Land”
• Rocky (dirt-like and metal materials)
• Small
• Dense
• Few moons
• No Rings
Mercury Venus
Earth
Mars
Terrestrial Planets
Mercury
Venus
Earth
Mars
The Speediest Planet- Travels
at 29.7 miles/sec.
The Twin Planet- roughly the same
size as Earth and visible from
Earth without a telescope
The Home Planet - only planet
known to have an atmosphere
that sustains life
The Red Planet - an iron surface is
blown around by storms
The Gas Giants
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Outer Planets (Farthest from sun)
• Jupiter, Saturn, Uranus, Neptune
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Made of gas and liquid
• HUGE
• Low densities (Saturn floats in water)
• Lots of moons
• All of them have rings
The Gas Giants
Jupiter
The Giant Planet- All the other planets
could be squeezed inside of it!
Saturn
The Ringed Planet- has the most (and
the largest) rings
Uranus
The Tilted Planet- orbits on its side
Neptune The Windy Planet- fiercest winds
blowing up to 1400 mi/hr. Blue color,
Named for the Roman God of the Sea
What about poor Pluto?
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Now considered a dwarf planet
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2nd largest dwarf planet we know of
• Eris is bigger, Ceres is another
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Mass is about 1/5 that of our moon
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Made of Ice and Rock (Very Cold)
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Orbit is highly elliptical and
sometimes dips into Neptune’s orbit
The Dwarf Planets
Here’s our solar
system........
So putting it all together.....