Download Planets and Other Space Rocks Notes

Planets and Other
Space Rocks
First Some Fun Facts about Orbit and
Rotation
• The Sun, planets, and large moons all
orbit and rotate in the same way.
• All planets orbit the Sun in the same
direction (counterclockwise).
• The orbit in elliptical orbits that are
almost circular, and in the same plane.
• The Sun and most of the planets rotate
on their own axis in the same direction,
counterclockwise.
• Most of the major moons orbit their planet in
the same direction the planet rotates.
Types of Planets
• There are 2 Types of Planets:
• Inner or Terrestrial
• Outer or Jovian
Inner Planets
• Inner or Terrestrial Planetssmall, rocky planets close to the
Sun, and are relatively close
together.
• These planets are:
• Mercury
• Venus
• Earth
• Mars
Outer Planets
• Outer or Jovian (Gas) PlanetsLarge, gas-rich planets far from
the Sun. they are relatively far
apart.
• These Planets are:
• Jupiter
• Saturn
• Uranus
• Neptune
Mercury
• The smallest of the planets, and the
closest to the Sun.
• Made of rock and metal, mostly iron.
• It has no moons and no atmosphere.
• A year is 87.9 Earth days.
• Daytime lasts 3 months and hits
temperatures of 425℃.
• Nighttime lasts 3 months and is as
cold as −150℃.
Venus
• The only planet in our solar system that is similar to
Earth in size.
• Covered in thick clouds that make the surface
invisible to our eyes.
• It is made mostly of rock and metal.
• It has no moons.
• The atmosphere is thick and heavy, if a human tried
to walk on the surface, they would be crushed.
• A year is 224.7 Earth days.
• It rotates slowly, in the opposite direction of Earth.
Each day is 243 Earth days long.
• The surface temperatures are 470℃, making it the
hottest planet in the solar system.
Earth
• Made mostly of rock and metal.
• Earth has 1 noticeable moon,
which is large in size.
• The size of the moon relative to the
size of Earth is very unusual for our
solar system.
• 75% of the surface is covered by
water.
• It is the only planet that can
sustain life on the surface.
Mars
• The inner planet that is furthest from the Sun.
• It has 2 moons: Phobos and Deimos.
• There is evidence of dried lakes and rivers on the planet.
• Made mostly of rock and metal.
• Its has frozen carbon dioxide on the surface, mostly at the poles.
• Just like Earth, the orbit and tilt of the planet allows it to have
seasons.
• The atmosphere is very thin, it is similar to being at the top of
Mount Everest.
• There is not enough oxygen for humans to breathe.
• A year is 680 Earth days, but a day is only 37 minutes longer than
Earth’s.
• The daytime temperature is 20℃ (68℉), and nighttime
temperature is −140℃ (−220℉)
Jupiter
• The largest planet in the solar system.
• 2-3 Earths could fit inside the Great Red Spot, a giant long-lived
storm. The storm has been going on for at least 300 years. It is the
largest story in the solar system.
• Has thin, faint rings.
• Made of hydrogen and helium.
• It has no solid surface, it is made entirely of gas.
• The increasing gas pressure deeper inside Jupiter would
crush you way before you go the core.
• Has at least 63 moons, 4 of them are as large as planets.
• It is the planet with the most moons.
• It year is more than 12 Earth years, but a day is less than 10
hours.
• The temperature at the top of the clouds is −148℃.
Saturn
• Made of hydrogen and helium, and has no
solid surface.
• It has at least 60 moons, including one with a
thick atmosphere covered completely by
clouds (Titan).
• Mimas, one if its moons looks like the Death Star.
• It has the biggest, brightest rings in the solar
system that can be seen with a small
telescope.
• A year is 29.5 Earth years, and a day is 10.2
hours.
• The temperature at the top is −178℃.
• It has a tilt, so it has seasons like Earth, but
they are mild.
Uranus
• It has faint rings.
• Made of hydrogen, helium, water, ammonia, and
methane.
• Has 5 moons
• The planet, rings, and moon orbits are all tipped on
their side.
• Scientists think this was due to a collision while the planet
was being formed.
• Its year is 84 Earth years, and day is 17.2 hours.
• Because of the tilt, the poles get daylight for ½ of Uranus’
years, and night for the rest of the year.
• The temperature at the top is −213℃
Neptune
• The furthest planet from the Sun.
• Made of hydrogen, helium, ammonia, and methane.
• It has faint rings.
• It has at least 13 moons.
• Triton is the only moon in the solar system that orbits a planet
backwards (opposite the direction of Neptune).
• Because of this, scientists think it may have been a captured planet.
• Its year is just under 165 Earth years, and its day is just
over 19 hours.
• The temperature at the top is −213℃.
• It has a tilt, so it has seasons like Earth, but they are mild.
What About Pluto?
• As of 2006, Pluto is no longer considered a
planet, but it is now a “Dwarf Planet”.
• Dwarf Planet- an object orbiting the Sun
that is large enough for its own gravity to
cause it to be round, but has not cleared out
the area in its orbit.
• One dwarf planet has been discovered in the
asteroid belt, Ceres.
• Asteroid Belt is located between Mars and
Jupiter.
• 4 dwarf planets (including Pluto) have been
fount in the Kuiper belt.
• The Kuiper Belt is a ring of comets that is located
beyond Neptune.
What is an Asteroid?
• Asteroid- a small rock orbiting
the sun.
• They are located mostly in the
asteroid belt.
What are Meteors, Meteoroids, and
Meteorites?
• Meteoroid- a small asteroid, typically
boulder sized or smaller.
• Meteor- when a meteoroid hits the
Earth’s atmosphere.
• Shooting stars are actually meteors that
are burning up as they are traveling
through the Earth’s atmosphere.
• Very bright ones are called fireballs.
• Meteorite- a piece of meteor that
lands on Earth.
• Most are small.
A small meteorite left a crater t600 feet
deep and 1,200 meters wide. It is located in
Winslow Arizona, and is called Meteor
Crater.
What is a Comet?
• Comet- small bodies orbiting the sun.
• Mostly made of ice water, ammonia,
and methane mixed with rick.
• Most are located in the Kuiper Belt
beyond Neptune, or farther out in the
Oort Cloud (the edge of our Solar
System).
• Example- Haley’s Comet
• Comets don’t get tail until they enter
the inner solar system.
• This rarely happens.