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The Planets and the Solar System
The solar system was born about 4.5 billion years
ago, when something disturbed and compressed a
vast cloud of cold gas and dust. The disturbance
may have been a collision with another cloud, or a
shock wave from an exploding star.
Inner (terrestrial) planets
Mercury
Venus
Mars
Earth
All of the inner planets have:
•Rocky crusts
•Dense mantle layers
•Very dense cores
Mercury
•Mercury is the closest planet to the Sun.
•It has a surface covered in craters
•Magnetic field is about one percent as strong
as Earth’s.
Mercury
•A year on Mercury lasts for only 88 Earth
days.
•Temperature can reach up to 400°c on its
sunlit side and nearly -200°c on its dark side.
Venus
•Is considered Earth’s sister planet
•Landscape dominated by volcanic features,
faulting, and craters.
•Weak or nonexistent magnetic field
Venus
•A year on Venus is 225 Earth days long.
•A day on Venus is 243 Earth days long
•Temperatures can reach up to 475°c because the
sun’s heat cannot escape through the thick
atmosphere, which acts like a greenhouse covering
the entire planet.
Earth
•Volcanoes, earthquakes, oceans, and weather still
form and reform Earths surface.
•Earth has a strong magnetic field.
•365.25 days for it to complete one revolution
around the Sun.
•23 hours and 56 minutes for a day
Earth
•Earth’s temperature can range from about 55°c
(130 °F) to -90°c (-130°F).
•only planet in the Solar System known to contain life.
•Earth is the only planet to contain water in all three
forms.
Mars
•The planet has a rusty surface and a pink sky. It is
covered in rocks and impact craters, and the solar
system's biggest volcano, Olympus Mons.
•Weak or nonexistent magnetic field
•A year on Mars is 687 Earth days.
•A day on Mars is 24 hours and 37 minutes
Mars
•Temperatures range from 25°c to -125°c.
•It once had flowing water.
•A small red planet with a very thin atmosphere of
carbon dioxide.
Asteroid Belt is between
Mars and Jupiter
The Outer Planets
And Pluto
(Gas Giants)
Uranus
Saturn
Jupiter
Neptune
Uranus Neptune
Saturn
Jupiter
The Gas Giants:
1. Are much larger.
2. Do not have solid surfaces.
3. Are composed mainly of the light elements
hydrogen and helium (gaseous planets).
4. All have a three-layered structure.
5. All have ring systems.
Jupiter
•No solid surface
•Colored zones and belts
•11.9 Earth years for one complete orbit.
•Strongest magnetic field
Jupiter
•Temperature increases with depth.
•Largest planet in the solar system with over
twice the mass of all other planets combined.
•Great Red Spot: a giant storm about twice
the size of Earth.
Saturn
•No solid surface
•Colored zones and belts
•30 Earth years for one complete orbit.
•Weaker magnetic field than Jupiter, but
still stronger than Earth
Saturn
•Temperature increases with depth.
•Most visible ring system in the solar system
•Very low density; could float on water.
Uranus
•No solid surface
•It is tipped almost completely over on its side.
•Magnetic field is not aligned with its poles, but
is off by about 60 degrees; almost as though it
was upright.
Uranus
•84 Earth years for one orbit.
•Average surface temperature is -200°c and
increases with depth.
Neptune
•No solid surface
•Magnetic field is tipped 47 degrees in relation
to its axis of rotation.
•165 Earth years for one orbit.
Neptune
•Average surface temperature is -225°c and
increases with depth.
•Winds have been clocked up to 2,000 kilometers
an hour.
Pluto
•Reclassified as a dwarf planet or minor planet.
•Rocky surface is covered with methane ice.
•Debate whether or not a magnetic field exists
on Pluto.
•248 Earth years for one orbit.
Pluto
•Temperatures range between -210°c to -235°c.
•Pluto is smaller than our moon.
•Its moon Charon is half its size.
•Axis is on its side and it rotates backwards.
•The sun appears as only a very bright star due to
its average distance of 39.5 astronomical units.