Transcript The Inner Planets of Our Solar System

Objects in
Our Solar System
Name the planets as they go around the sun.
Essential Vocabulary
Rotation – the time it takes to
spin on its axis
This makes one DAY
Revolution – the time it takes
to orbit the sun once
This makes one YEAR
The Inner Planets
• Mercury, Venus, Earth and Mars
• Known as terrestrial planets because
they are made of rock
• Revolve around the Sun and rotate on
their axis
• Closest planets to the Sun
The Outer Planets
Jupiter, Saturn, Uranus, and
Neptune
Gas Giants – composed
mostly of Hydrogen and
Helium
All have rings
Revolve around the sun and
rotate on their axis.
NOT TO SCALE!
The Sun
Largest thing in our
A ball of glowing gas! solar system
– 99.8% of the mass
of the solar system
No solid surface
– 75% Hydrogen and
25% Helium
Rotates on its axis
every 25 – 38 days
Located in the
center of the solar
system
The Moon
Our moon is named Luna
Spherical
About 2400 miles across.
All moons are made of
rock.
Moons orbit their planets
in the same direction as
the planets’ rotations
Galilean Moons
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The largest of the
many moons of Jupiter
Discovered by Galileo
Galilei on Jan. 7, 1610
Galilean Moons
Among the most massive rocky objects in the
Solar System, with a radius larger than Mercury
or any of the dwarf planets.
Galilean Moons
Io (3,642 km) With over 400 active volcanoes, Io is the most
geologically active object in the Solar System.
Europa (3121.6 km) The smooth surface includes a layer of ice,
while the bottom of the ice is theorized to be liquid water.
Ganymede (5262 km) largest natural satellite in the Solar
System, a salt-water ocean is believed to exist nearly 200km
below Ganymede's surface, sandwiched between layers of ice.
It has a thin oxygen atmosphere.
Callisto (4820 km) Callisto is is surrounded by an extremely thin
atmosphere composed of carbon dioxide and probably
molecular oxygen. Investigation revealed that Callisto may
have possibly a subsurface ocean of liquid water at depths
greater than 100 kilometers.
Meteoroids
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Meteors are rocky
fragments of comets,
planets, moons, or
asteroids.
Travel through space
without an orbit.
Meteors
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Meteoroids that have
entered an atmosphere
Friction with the
molecules in the
atmosphere cause it to
burn
Commonly called
“shooting stars”
Meteorites
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Any part of a meteoroid
that survives passage
through the atmosphere
and lands on the surface of
a planet or a moon.
Largest meteorite found on Earth
Hoba, Namibia
Comets
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Mixture of ices (both water and frozen
gases) dust, and rocks
Have an elliptical orbit around the sun
– When they are in the inner solar system
the radiation from the sun causes a tail to
form.
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Due to solar winds, the tail always points away
from the sun
Asteroids
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Left over materials from
the formation of the Solar
System
Composed of rock or
metal
Smaller than a planet but
larger than a meteor
No evidence of an
atmosphere
Asteroid Belt
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Most are located
in the asteroid
belt between
Mars and
Jupiter: 2 – 4 AU
probably more
than a million