Transcript The Inner Planets

The Inner Planets
The inner planets are all the
planets that are inside the asteroid
belt.
These are Mercury, Venus, Earth,
and Mars.
They are called the terrestrial
planets because they all have rocky
surfaces.
The word terrestrial comes from
the Latin word terra, which means
“rock”.
Mercury
• Mercury is the closest planet to the Sun.
• It has the fastest orbit of any of the planet,
finishing in just 88 days.
• Mercury is about the same size as our moon,
and like our moon, is covered in craters.
• It has no moons!
• One day on Mercury is about 58.5 Earth days.
• The name “Mercury”
comes from the
Roman messenger
god. He was a god
with wings on his
shoes, and he flew
very fast. Because the
planet Mercury has
the fastest orbit,
scientists named it
after this Roman god.
• Because Mercury is such a small planet,
it has almost no gravity. That means that
the planet can’t hold air and gas to make
an atmosphere. Also, solar winds from
the nearby sun blow away the air.
Mercury has almost no air!
Venus
• Venus is the second planet from the sun.
• A day on Venus takes longer than a year!!
• Venus is very similar to Earth in many ways:
they have similar gravity, they are made of the
same materials, and they are about the same
size.
• There are no moons.
• Venus gets its name from the Roman goddess
(female god) of love and beauty. People
named the planet after her because they
thought the colors and clouds on Venus
looked beautiful.
• It is extremely hot on Venus. It is even
hotter than Mercury. This is because of
something called the greenhouse effect.
• Venus is covered in clouds, and it traps the
hot air close to the planet so it has nowhere
to go, so it just gets hotter and hotter.
• Venus is very cloudy, but it
is just too hot to rain.
Earth
• It is the third planet from the Sun
• It has one moon.
• One day on Earth is 24 hours; one year is
365 days.
• Earth is the only planet we know that has
life.
• Earth is the biggest of all the inner
planets.
• Earth is the only planet not named after
a Roman god.
• Earth is a word that means “ground,”
“dirt,” or “soil.”
• When Earth got its name, people didn’t
know it was 70% covered in water, or
they probably would have called it
Oceania.
• Earth is the densest planet in the solar
system. That means that it has the most stuff
in the smallest space. For example, pretend
you have two loaves of bread the same size. If
you squeeze one into a small ball, one is
bigger and one is smaller. They are still the
same amount of bread, but the smaller one is
more dense.
Mars
• Mars is the fourth planet from the sun, and
the last of the inner planets.
• Mars is about half the size of Earth.
• It has two moons, named Phobos and Deimos.
• It is called “The Red Planet” because of its red
color, which comes from iron in the ground.
• The name Mars comes from the Roman god of
war.
• Scientists believe that there once were
lakes, rivers, and even oceans on Mars,
because of what the land looks like now.
• Now the only water on Mars is found
frozen in the polar ice caps.
• The largest volcano in the Solar System is on
Mars.
• It is called Olympus Mons, and it is 26 km
high. It is 500 km across, and has cliffs over 6
km high all around it.
• It’s over 3x the size of Mt. Everest!
The End!