Planets & Dwarf Planets The Solar System Planets & Dwarf Planets

Solar System the collection of eight planets and their moons in orbit around the sun, together with smaller bodies in the form of asteroids, meteoroids, and comets. AKA: anything that orbits the sun is part of the solar system

According to this theory, our own solar system formed about 4 According to this theory, our own solar system formed about 4.6 billion years ago, and others are forming today in distant nebulae.

The planets Terrestrial/Rocky/Inner “Earth-Like” Mercury, Venus, Earth, Mars Made of solid rock Have few or no moons Small Short orbital period

Jovian/Gas Giants/Outer “Jupiter-Like” Jupiter, Saturn, Uranus, Neptune Made of gas Have many moons Have rings Large Long orbital period

The Solar System You must know the order of the planets

Dwarf Planets a celestial body orbiting a star that is massive enough to be rounded by its own gravity but has not cleared its neighboring region of planetesimals and is not a satellite.  AKA: it is not a moon (it does not orbit another planet), but its orbit intersects the orbit of another planet The first five recognized dwarf planets are Ceres, Pluto, Eris, Makemake and Haumea.

Things to ponder… Is Pluto always the farthest “planet” from the sun?

To Do: Solar System Trading Cards Game Solar System Spacing Learn more about each of the planets Solar System Spacing Learn just how vast the solar system really is!

Smaller Members of the Solar System Asteroids Comets Meteoroids, Meteors, and Meteorites

Asteroids Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets. Asteroids are material left over from the formation of the solar system. Most likely, asteroids are material that never coalesced into a planet

Asteroid Belt Most asteroids lie between the orbits of Mars and Jupiter (3-6 year orbital periods)

Comets dirty snowballs or "icy mudballs“ Rocky and metallic materials held together by ices (both water and frozen gases) and dust Extremely elliptical orbits (long orbital periods)

Parts of a Comet *glue-able slide

A Comet’s Tail Always points away from the Sun

Where do comets come from? Kuiper Belt: Short period comets Oort Cloud: Long period comets

Halley’s Comet Short period comet Last passed by in 1986 Orbital period = 76 years Last passed by in 1986 When will the next pass be? How old will you be?

Meteoroids, Meteors, and Meteorites Meteoroids (in space) The smallest particles orbiting the sun, most are no larger than grains of sand Meteors (in the atmosphere/ shooting stars) Meteoroids that enter Earth's atmosphere. Meteorites (on the ground) Meteors that do not burn up in the atmosphere and impact Earth’s surface

Meteorites Meteors that do not burn up in the atmosphere and impact Earth’s surface Leave impact craters Barringer Crater, Arizona

Extinction of the Dinosaurs?

To Do: 23.4 Assessment on page 664 Restate the question. Write in complete sentences.