other objects in the solar system. so far, we have studied: –planets –stars which make up...
TRANSCRIPT
Other Objects in the Solar System
• So far, we have studied:– Planets– Stars
• Which make up galaxies, constellations and asterisms
• The solar system also contains:– Moons– Asteroids– Meteors– Comets
What Else is Out There?
Satellites
• Objects that revolve around planets are called satellites
• Satellites can be– Natural (not man-made)
• Example: moons
– Artificial (man-made)• Example: GPS and TV satellites
Moons
• A moon is a natural satellite
• The moons of other planets weren’t discovered until after the telescope was invented
• Earth’s moon has been visited six times between 1969 and 1972
Planet # of known moons
Mercury 0
Venus 0
Earth 1
Mars 2
Jupiter 39
Saturn 30
Uranus 20
Neptune 8
Pluto 1
Earth Jupiter (Europa & Io)
Mars (Phobos & Deimos)
Pluto (Charon)
Eclipses
1. Solar Eclipse- The Moon passes between the Earth and the Sun- This blocks our view of the Sun- Only occurs during New Moon
2. Lunar Eclipse- The Earth passes between the Moon and the Sun- The Moon is plunged into darkness as Earth’s shadow
moves across it- Only occurs during Full Moon
Asteroids• Asteroids are small, rocky objects that never
formed into planets
• The ring of asteroids between the orbits of Mars and Jupiter is the asteroid belt
• The orbits of some asteroids cross the path of Earth and pose a potential collision hazard
• The largest asteroid, Ceres, is 1000 km in diameter
Eros
Ceres
Asteroid Belt
Meteors, Meteoroids and Meteorites
• A meteoroid is a lump of rock or metal that is pulled through Earth’s atmosphere
• Friction between the meteoroid and the atmosphere causes the meteoroid to heat up
• Small meteoroids will vaporize
• Large meteoroids can burn up and generate enough light to become visible
Meteors, Meteoroids and Meteorites
• This fireball appears as a bright streak in the sky and is called a meteor– Sometimes called a shooting star
• Fragments of the meteor that are large enough or tough enough don’t burn up and strike Earth’s surface.
• A meteorite is a meteor remnant that survives to strike the Earth’s surface
Meteor Meteor Shower
The Barringer Meteorite Crater
4,000 ft
570 ft
Comets
• A comet is a chunk of frozen ice and dust that travels in a very long orbit around the Sun
• Occasionally, a comet gets bumped from its orbit and passes close to the Sun
• The frozen gases that make up the comet melt and evaporate as it approaches the Sun
• This forms a bright glowing tail that can be thousands of kilometers long and visible for several months
Halley’s Comet
Comet Hyakutake