Name: ______
Planet Fact Sheet
The Inner or Terrestrial Planets
• Mercury, Venus, Earth and Mars share certain characteristics:
– All are rocky bodies.
– All have solid surfaces.
– Except for Mercury all have at least a thin atmosphere
• They are called Terrestrial planets because of their resemblance to Earth.
Mercury
ü Named after Speedy messenger of Roman gods
ü Closest planet to the sun
ü Revolution around the sun = 88 Earth days
ü Rotation on its axis = 59 Earth days
ü Crater-covered surface with steep cliffs
ü Almost no atmosphere
Venus
ü Named after Roman goddess of beauty and love
ü 2nd closest planet from the sun
ü Revolution around the sun = 224 Earth days
ü Rotation on its axis = 243 Earth days
ü Venus and Earth are of almost the same size, mass, and density, but differ greatly in other areas.
ü Surface pressure = 91 times more than Earth’s
Earth
ü 3rd planet from the sun
ü Revolution around the sun = 365 days
ü Rotation on its axis = 24 hours
ü Earth has one large moon.
ü Geologic records indicate that over the last 250 million years, Earth’s surface has undergone many changes.
Mars
ü Named after Roman god of war
ü 4th planet from the sun.
ü Mars is about 50% farther from the sun than Earth is.
ü Its orbital period is 687 days
ü It rotates on its axis every 24 hours and 37 minutes.
ü Mars’s seasons are like Earth’s seasons because the same axis.
ü Has the largest volcano in the solar system, Olympus Mons.
ü About half the size of Earth. No geological activity likely now. No magnetic field.
ü Evidence of massive water erosion some time in the past. Scientists are searching for liquid water now.
ü Two satellites, Phobos and Deimos
ü (possibly captured asteroids)
ü High winds often create dust storms
The Outer or Jovian Planets
• Jupiter, Saturn, Uranus and Neptune share certain characteristics:
– All are large, gaseous bodies.
– All have very thick atmospheres, with possibly liquid interiors and solid cores
– All have rings
• They are called Jovian planets because of their resemblance to Jupiter.
Jupiter
ü Named after the king of the Roman gods
ü 5th planet from the sun
ü Jupiter is the largest planet in the solar system and has a mass more than 300 times that of Earth.
ü The orbital period of Jupiter is almost 12 years. Jupiter rotates on its axis faster than any other planet—once every 9 hours and 50 minutes
ü Jupiter has at least 60 moons.
ü It also has several thin rings that are made up of millions of particles.
ü Great Red Spot = hurricane-like storm (as much as 20,000 years old)
ü Very high atmospheric pressure
ü Giant magnetic field
Saturn
ü Named after a Roman god
ü 6th planet from the sun
ü Rotates every 10 hours and 30 minutes
ü Revolves around the sun every 29.5 years
ü Surrounded by rings made of icy particles; at least 7 major rings
ü Violent atmospheric storms
ü Very cold
ü Has a large magnetic field
ü Lowest density of all the planets
ü The orbital period of Saturn is 29.5 years.
ü Saturn rotates on its axis every 10 h and 30 min.
Uranus
ü Named after the father of Saturn in Roman mythology
ü 7th planet from the sun
ü Rotates every 17 hours
ü Revolution around sun every 84 years
ü Extreme atmospheric pressure; atmosphere is 11,000 kilometers thick
ü Rotates on its axis at a 90 degree angle; appears laying on its side
ü Rings of methane ice surround it
ü Has at least 24 moons and at least 11 thin rings
Neptune
ü Named for the Roman god of the sea
ü 8th planet from the sun
ü Revolution around the sun every 164 years
ü Rotation 16 hours
ü Surface-ocean of water, liquid methane, and rocky core
ü Five rings surround Neptune made of dust particles formed from meteorites