The Solar System

Our Solar System Is a group of planets orbiting a central star that we call the Sun The solar system contains the Sun, 8 planets, 3 dwarf planets, and various moons, asteroids, meteors, comets and space debris In 2006 the International Astronomical Union decided to remove Pluto as a planet and create a new category called dwarf planets, due to: the discovery of an object bigger then Pluto (a dwarf planet called Eris) Pluto not having the same characteristics as other planets (has an irregular orbit, isn’t the most influential object in its region in space, etc.)

The Sun The Sun is the largest thing in our solar system It is 109x the size of the Earth and 330 000x heavier!! You could fit over a MILLION Earths in the Sun! All the planets are bound to the Sun by gravity

Rotation vs. Revolution rotation = term used to describe a planet spinning on itself (its axis) it takes the Earth 1 day (24 hrs) to rotate once the Earth doesn’t rotate on its true axis but tilted on a 23.5 angle revolution = the movement of a planet or body around another object the Earth revolves around the Sun it take the Earth 365.24 days to revolve around the Sun once

Revolution & Rotation of the Planets All the planets in the solar system revolve around the Sun in a counterclockwise direction in slightly elliptical (oval) orbits All planets also rotate in a counterclockwise direction (well, almost all)

------------------ Gas giants ------------------ The Solar System ------------------ Gas giants ------------------ Terrestrial / inner planets

Mercury Closest planet to the Sun A rocky ball only slightly bigger than the Earth’s moon Made of rock, covered in craters Takes only 88 Earth days to orbit the Sun Has virtually no atmosphere Temperature -180 to 426C Extreme temperatures cause huge cracks to form on the planet’s surface

Venus Size and composition are similar to Earth Rocky surface with a thick atmosphere of CO2 Rain is sulfuric acid on this planet, not water! Takes 244 Earth days to spin on its axis… sloooow Very hot (470C) due to its thick atmosphere

Earth Only planet to support life that we know of Called the blue planet since it’s mostly covered with water Temperature -85 to 58C Rocky core Atmosphere composed mainly of N2, O2 Only planet to have water in all 3 states One moon

Mars Called the red planet due to iron oxide in its surface Half the size of Earth Temperature -120 to 30C Rocky surface with a thin atmosphere of mainly CO2 Massive volcano named Olympus Mons is almost 3x bigger than Mt. Everest! Canyon 8 km deep Winds can exceed 900 km/h Dust storms can last for weeks 2 moons, Phobos & Deimos

Jupiter Largest planet It’s 2.5x heavier than all the planets combined! Has a Great Red Spot, as big as 3 Earths, that’s a giant storm Solid core, but mostly made of H2, He, and CH4 (methane) gases Takes only 10 hrs to rotate on its axis but 11.9 yrs to revolve around the Sun Has very thin rings made of ice particles Temp -150C More than 60 moons!!

Saturn Made mostly of H2 and He gases 2nd biggest planet Most elaborate ring system, made of dust and ice particles (some are as big as a house!) Made mostly of H2 and He gases Could float in a bath tub if you could find one big enough! Temp -170C Many, many moons

Uranus 3rd biggest planet in the solar system Ok, we all know the joke, but it’s YUR-ah-nus Uranus 3rd biggest planet in the solar system Blue-green colour from methane in its atmosphere Tilted on its side, so it looks like it’s rolling through its orbit Rotation is opposite to other planets Also has a ring system Takes 84 Earth years to orbit the Sun Temperature -215C

Neptune Gas giant Similar in composition and atmosphere to Uranus Darker blue colour Thin rings made of ice particles Takes almost 165 Earth years to orbit the Sun Temp is -235C, yikes! 13 known moons Named after the Roman god of the sea

Dwarf Planets Adopted in 2006 Dwarf planets are objects that: orbit the sun have enough mass to become round are not large enough to have an impact on their area There are currently 3 dwarf planets in our solar system: Pluto, Eris, & Ceres