Transcript On Earth, impact craters are generally erased by other geologic

• The four planets that are closest
to the sun are called the
TERRESTRIAL PLANETS.
• These planets have rocky crusts
and dense mantles and cores.
• Scientists study Earth to learn
more about other planets.
• All of the terrestrial planets
formed in similar ways and
follow similar patterns.
• All terrestrial planets have
layers.
– The heaviest materials form the
core.
– Lighter rock formed a mantle
around the core.
– The lightest rock rose to the
surface and formed a crust.
• Tectonics is the processes of
change in a crust due to the
motion of hot material
underneath.
• The crusts of the planets can
be twisted, wrinkled up, or
stretched out by the mantle.
• Volcanism occurs when
molten rock moves from a
planet’s hot interior onto its
surface.
• When the inside of a planet
cools enough, no more molten
rock reaches the surface.
• Weather or small impacts
break down rocks.
• The broken material is moved
by a group of processes called
erosion.
• The material may form dunes,
new layers of rock, or other
features.
• A small object sometimes hits
a planet’s surface so fast that
it causes an explosion.
• The crater it leaves behind
can be 10 times larger than
the object that created it!
• Earth’s crust is split into large
pieces called tectonic plates.
• These plates are moved by
Earth’s hot mantle.
• Mountains, valleys and other
features form as the plates move.
• On Earth, magma often builds up
into mountains and eventually
erupts as lava.
• On Earth,
weathering and
erosion create
sedimentary
rocks, sand
dunes, fill in
lakes, and
change the
topography.
• On Earth, impact craters are
generally erased by other
geologic processes.
• Impact craters can be found
under lakes.
• Mass: 6 x 1024 kg
• Diameter: 12,800 km
• Average distance from the
sun: 1 AU
(150 million km)
• Orbits in: 365 days
• Rotates in: 24 hours
• Read pages 725-732 or 85-92E
and learn more about how the
four processes, that we
discussed with earth, shaped
Mercury, Venus, and Mars.
• Complete these pages in your
Planet Book.
• Work on your cover - must be
colored and very well done