SOLAR SYSTEM
- The solar system we live in includes :
- the Sun
- planets
- other small objects
- Astronomical unit: average distance between the Earth and the Sun (150 million km, symbol, AU)
- Until the 17 century the universe was thought to have only 8 bodies; Earth, Mercury, Venus, Mars, Saturn, and Jupiter. These are the only bodies you can see from Earth.
- Inner planets: closer together than the outer planets, also known as terrestrial planets since they have surfaces that are dense and rocky.
- Outer planets: farther apart than inner planets, Are composed mostly of gases, Jupiter, Saturn, Uranus, and Neptune are known as gas giants. These pants atmospheres blend into their dense interiors.
- the Sun
- planets
- other small objects
- Astronomical unit: average distance between the Earth and the Sun (150 million km, symbol, AU)
- Until the 17 century the universe was thought to have only 8 bodies; Earth, Mercury, Venus, Mars, Saturn, and Jupiter. These are the only bodies you can see from Earth.
- Inner planets: closer together than the outer planets, also known as terrestrial planets since they have surfaces that are dense and rocky.
- Outer planets: farther apart than inner planets, Are composed mostly of gases, Jupiter, Saturn, Uranus, and Neptune are known as gas giants. These pants atmospheres blend into their dense interiors.
INNER PLANETS
- Mercury, Venus, Earth, Mars.
- Our of all the planets Venus seems to be the most similar to Earth.
- Venus is also not similar to Earth because it has retrograde rotation while Earth has prograde rotation.
- retrograde rotation : Counter-clockwise spin of a planet as seen from a planets north pole, same as the Sun's rotation.
- prograde rotation : Clockwise spin of a planet or moon as seen from above the planet's north pole.
- Our of all the planets Venus seems to be the most similar to Earth.
- Venus is also not similar to Earth because it has retrograde rotation while Earth has prograde rotation.
- retrograde rotation : Counter-clockwise spin of a planet as seen from a planets north pole, same as the Sun's rotation.
- prograde rotation : Clockwise spin of a planet or moon as seen from above the planet's north pole.
OUTER PLANETS
- Jupiter : largest of the outer planets, There have been five missions to Jupiter: 2 pioneer missions, 2 voyager missions, and the Galileo mission
- Saturn : Second largest of outer planets, Saturn has the largest rings of all of the planets.
- Uranus : smallest of outer planets, has the most tipped over axis of all the planets, with about a 90 degree tilt! Discovered in 1781 by William Herschel.
- Neptune : By noticing the impurities in the orbit of Uranus, suggested that another planet was making the impurities with its gravitational force. This is how Neptune was discovered in 1846.
- Saturn : Second largest of outer planets, Saturn has the largest rings of all of the planets.
- Uranus : smallest of outer planets, has the most tipped over axis of all the planets, with about a 90 degree tilt! Discovered in 1781 by William Herschel.
- Neptune : By noticing the impurities in the orbit of Uranus, suggested that another planet was making the impurities with its gravitational force. This is how Neptune was discovered in 1846.
MOONS
- Our moons name is Luna.
- Before scientists had rock samples from the moon there were three popular explanations for the moons existence.
1) Moon was a body in space caught by earth's gravity.
2) The moon was formed at the same time by the same materials from the earth at the same time the earth was formed.
3) When earth first formed it was spinning so fast that a chunk flew off and it became the moon.
- Phases : Change in the sunlit area of one celestial body seen from another celestial body.
- Eclipse : Event where the the shadow of one celestial body falls on another.
- Before scientists had rock samples from the moon there were three popular explanations for the moons existence.
1) Moon was a body in space caught by earth's gravity.
2) The moon was formed at the same time by the same materials from the earth at the same time the earth was formed.
3) When earth first formed it was spinning so fast that a chunk flew off and it became the moon.
- Phases : Change in the sunlit area of one celestial body seen from another celestial body.
- Eclipse : Event where the the shadow of one celestial body falls on another.