Minor Bodies of the Solar System Notes.notebook October 13, 2016
Pluto – discovered in 1930; made of ½ ice and ½ rock
‐9th planet until 2006; now classified as a dwarf planet
‐doesn’t have properties of gas planets either
‐while at perihelion Pluto is closer to the sun than Neptune
‐rotational axis is tipped so far over that the N pole actually points S of its orbital plane
‐theory has it that it could have possibly been a moon of Neptune or is related to a comet
Pluto
Pluto's Orbit
Minor Bodies of the Solar System Notes.notebook October 13, 2016
Into the Asteroid Field
Meteors and Asteroids• Asteroids
‐leftovers from the formation of the solar system
‐range in size from 2km to about 1000km
‐interplanetary material falls toward earth and enters the atmosphere is a meteoroid
‐when it burns up in the atmosphere producing a streak of light called a meteor
‐when it hits the ground it is called a meteorite
Minor Bodies of the Solar System Notes.notebook October 13, 2016
Comets
small, icy bodies w/ highly eccentric orbits around the sun
made of ice and rock consists of a coma ,the nucleus, and the tail
tail always points away from the sun b/c of particles
and ions coming from the sun and pressure of radiation from the sun
Comets
Comet Hartley 2, taken by NASA on November 4, 2010, by Deep Impact spacecraft
Comet Tempel 1, taken by Deep Impact on July 4th, 2005
Comet West, 1975
Minor Bodies of the Solar System Notes.notebook October 13, 2016
More AboutComets
Kuiper belt and Oort cloud are two clusters of comets
Kuiper belt is close to PlutoOort cloud is more than 100,000AU from the sunCollisions among large objects sometimes send
comets toward the inner solar system.
comets that repeatedly orbit into the inner solar system are known as periodic comets. Example Halley’s Comet when earth intersects a cometary orbit earth
experiences a meteor shower where particles from the comet burn up in the atmosphere
Question How do the planets move around the sun?
Minor Bodies of the Solar System Notes.notebook October 13, 2016
• 16th century Kepler proved that the planets orbited in ellipses counterclockwise and not complete circles— Kepler’s 3 Laws of Planetary Motion
• Kepler’s 1st Law of Ellipses: states that planets travel in elliptical orbits around the sun at one focus. This means the planet is not always the same distance from the sun. The point in a planet’s orbit where it is farthest from the sun is the aphelion, while the point nearest the sun is its perihelion.
> When the object is near the sun, it moves relatively rapidly. When the object is far from the sun, it moves relatively slowly.
> However, the area covered during the elliptical orbit around the sun is same, given equal amounts of time.
Kepler’s 2nd Law of Equal Areas: states that each planet moves around the sun in an orbit where at any point there is an equal area btw. the planet and sun. This law is true b/c the planet’s orbit is elliptical. The equal area law means that the speed at which planets travel around the sun is not constant.
Minor Bodies of the Solar System Notes.notebook October 13, 2016
• Kepler’s 3rd Law of Periods: states that the period (the time it takes a planet to orbit the sun) squared is = to the cube of its average distance from the sun.
P2 = a3
• The asteroid belt is located between Mars and Jupiter.• Meteoroid – chunk of metal/stone that orbits the sun.
(millions enter our atmosphere daily)• Meteor – streak of light that is produced by a burning
meteoroid.• Meteorite – a meteor that strikes the Earth’s surface.
Asteroid Belt
Minor Bodies of the Solar System Notes.notebook October 13, 2016
• 1. What keeps our solar system together?• 2. What force keeps planets in motion?• 3. What are the four inner planets?• 4. What are the five outer planets?• 5. Which is the sister planet to the earth?
Review
Minor Bodies of the Solar System Notes.notebook October 13, 2016