The Solar System See body of Powerpoint for image sources

2 Relative Sizes of the Planets, plus Pluto Image from Mercury Venus Earth Mars Not pictured, the dwarf planet Ceres Not pictured The dwarf planet Eris Jupiter Saturn Uranus Neptune

3 Image from Clean picture comparing relative sizes

4 Another perspective Image from Another perspective Renamed Eris

5 The Inner Planets Mercury Venus Earth Mars

6 Characteristics of the Inner Planets They are 4 planets closest to the sun: Mercury, Venus, Earth and Mars. Located inside Asteroid Belt Very similar to each other, they are small and have rocky surfaces. They are dense. Do NOT have rings Often called “terrestrial planets” because they resemble Earth, “terra-” means “Earth”

7 Mercury Size- about 38% of Earth’s diameter it is 4878 km Distance from sun- about 39% of Earth’s distance it is 58,000,000 km Surface- thin, hard rocky surface covered with many plains and craters Atmosphere- very thin, some sodium and other gases

8 Mercury(cont’d) Ability to support life- none, there is NOT any sign of life on Mercury, lack of water and oxygen along with hot temperatures make life unlikely Moons- none Rotation- 59 Earth days Revolution-.24 Earth years Daytime(sunlit side) temperature 430ºC Nighttime(shaded side) temperature -190ºC

9 Mercury Image on left from Image on right from

10 Venus Size- slightly smaller than Earth 95% of Earth’s diameter, it is 12,104 km Distance from sun- about 2/3 of Earth’s, it is 108,000,000 km from sun Surface- covered with rock similar to some parts of Earth, has volcanoes with lava flows and strange domes

11 Venus (cont’d) Atmosphere- Very thick and cloudy, mostly carbon dioxide, clouds partly sulfuric acid Atmospheric pressure is 90 times heavier than Earth’s and would crush a human

12 Venus (cont’d) Atmosphere continued- Mostly carbon dioxide so greenhouse effect is strong Has clouds of sulfuric acid Ability to support life- Life does NOT appear to exist on Venus, lack of water along with harsh temperatures and atmosphere make life on Venus unlikely

13 Venus (cont’d) Sometimes called “Earth’s twin” or “Earth’s sister planet” due to similarity Retrograde rotation- rotates “backward” from east to west (opposite of Earth) Rotates very slowly, one rotation takes about 8 Earth months and one revolution around sun takes about 7.5 Earth months (One day is longer than one year) Moons- None

14 Venus Phases of Venus Image from Image on left from

15 EarthEarth Size- 12,756 km diameter Distance from Sun- 150,000,000 km Surface- Crust is a solid rocky surface, 70% is covered by water Atmosphere- up to 100 km thick, made up of 78% Nitrogen, 21% Oxygen, 1% other gases

16 EarthEarth Ability to Support Life- Life does exist on Earth. Gaseous oxygen, liquid water and moderate temperatures are hospitable for life on Earth Rotation takes 24 hours Revolution takes days Earth has one moon

17 EarthEarth Image on left from Image on right from

18 Mars Size- 53% of Earth’s diameter, it is 6794 km Distance from Sun- about 1.5 times distance of Earth It is 228,000,000 km from sun Surface-Rocky surface with carbonite rocks high in iron, creating red color Polar ice caps contain frozen water and carbon dioxide

19 Mars Atmosphere- Very thin, with thin clouds Mostly carbon dioxide, only 1% of Earth’s atmospheric pressure Ability to support life- It is possible that primitive bacteria may have lived on Mars or may now live there but none has been found. Existence of liquid water makes life on Mars a possibility

20 Mars continued Has polar ice caps of frozen water and frozen carbon dioxide Rotation Earth days Revolution- 1.9 Earth years Mars has largest volcano in solar system, called Olympus Mons Moons- 2 Phobos and Deimos Image of Phobos from

21 Mars Image on left from Image on right from

22 The Outer Planets Jupiter Saturn Uranus pronounced “YOOR-a-nus” see Neptune Pluto (a dwarf Planet)

23 Characteristics of The Outer Planets These are the planets outside of the Asteroid Belt, they are: Jupiter, Saturn, Uranus, Neptune and the dwarf planets Pluto and Eris Jupiter, Saturn, Uranus, and Neptune are called “Gas Giants”. They are much larger than Earth and do not have solid surfaces

24 Characteristics of The Outer Planets Pluto and Eris are small and rocky, like the terrestrial planets. The gas giants do not have well-defined surfaces but have deep atmospheres that are typically about 75% hydrogen, 24% helium, and 1% other elements Gas giants likely have solid cores of rock, ice, frozen carbon dioxide and other compounds

25 Jupiter Size- diameter is 11 times Earth’s, It is 142,800 km Distance from Sun- 5.2 times further than Earth. It is 778,000,000 km Surface and atmosphere of gas and liquid it does not have a well-defined surface Has a deep atmosphere of about 86 % hydrogen,14 % helium, and tiny amounts of methane, ammonia, phosphine, water, acetylene, ethane, germanium, and carbon monoxide.

26 Jupiter continued Ability to support life- Lacks water, oxygen and moderate temperatures needed to support life. NO known life Largest planet in solar system with 300 times the mass of Earth Rotation-.41 Earth days (fastest) Revolution- 29 Earth years

27 Jupiter continued Moons- 17 (book), 63 (web), 16 that are 10 km or larger and many smaller ones(NASA), Europa may have water Has dark rings Great Red Spot is storm on Jupiter, twice as big as Earth

28 Jupiter Image on left from Image on right from Jupiter and moon Io

29 Saturn Size- About 9.44 times size of Earth. It is 120,540 km Distance from sun- About 9.5 times distance from sun as Earth. 1,427,000,000 km Surface and atmosphere of a gas giant, it does not have a well-defined surface but has syruplike mixture of helium and hydrogen and a thick atmosphere of gaseous helium and hydrogen

30 Saturn continued Ability to support life- Lacks water, oxygen, and moderate temperatures needed to support life Second largest planet in solar system Rotation Earth days Revolution- 29 Earth years

31 Saturn continued Moons- 19 (book), 34 (Web), 25 that are 10 km or larger plus additional smaller ones (NASA) Low density planet, could float in water Prominent rings- diameter of 250,000 km or more but only about 1 kilometer thick, mostly chunks of ice and rocks

32 Saturn Image on right from Image on left fromhttp://pds.jpl.nasa.gov/planets/images/full/saturn/saturn.jpg

33 Uranus pronounced “YOOR-a-nus” Size- About 4 times diameter of Earth. It is 51,200 km Distance from Sun- About 19 times farther from sun than Earth. It is 2,871,000,000 km Surface and atmosphere of a gas giant, it does not have a well-defined surface,

34 Uranus continued the surface of Uranus consists of blue- green clouds made up of tiny ice crystals of methane, and rock. The crystals of methane have frozen out of the planet's atmosphere. Uranus' atmosphere is about 83% hydrogen, 15% helium and 2% methane.

35 Uranus continued Ability to support life- Lacks water, oxygen, and moderate temperatures needed to support life, NO known life Rotation Earth days, is retrograde rotation like Venus, and rotates on side Revolution- 84 Earth years Moons- 18 (book), 27 (Web), 21named moons (NASA) Rings- 11 dark rings

36 Uranus Image on left from Image on right from

37 Neptune Size- Almost 4 times diameter of Earth. It is 49,500 km Distance from Sun- Almost 30 times farther from sun than Earth. It is 4,497,000,000 km Surface and atmosphere of a gas giant, it does not have a well-defined surface Neptune's composition is probably similar to Uranus': various "ices" and Silicates (rock) with about 15% hydrogen, some water, and a little helium

38 Neptune continued Atmosphere is mostly hydrogen and helium with a small amount of methane. Ability to support life- Lacks significant water, oxygen, and moderate temperatures needed to support life. NO known life.

39 Neptune continued Rotation Earth days Revolution- 165 Earth years Visible clouds in atmosphere Moons- 8 (book), 13 (web), 11 (NASA) 3 Very dark rings, 1 very faint ring

40 Neptune Image on left from Image on right from

41 Pluto Size- about 17% of diameter of Earth. It is 2200 km Distance from sun- more than 39 times farther than Earth. It is 5,913,000,000 kilometers Rocky, icy surface is very small Thin atmosphere of methane gas

42 Pluto continued Ability to support life- Lacks water, oxygen, and warmth needed for life NO known life Moons- 1 Charon (book), 3- Charon, Hydra and Nix (web and NASA) Rotation- 6.4 Earth days Revolution- 248 Earth years

43 Pluto Image on left from Image on right from

44 The Dwarf Planets Ceres - new dwarf planet, it was classified as the largest asteroid in the Asteroid Belt (it is between Mars & Jupiter). Say sir’eez Pluto - was classified as a planet, now classified as a dwarf planet Eris - new dwarf planet, past Pluto it is an icy body near the edge of our solar system. Say ee’ris

45 The Dwarf Planets and their Moons Image from

46 Planets and Dwarf Planets compared Dwarf planets are smaller than planets Both orbit the Sun Both are large enough that their gravity pulls them into the shape of a sphere Planets clear smaller objects out of their orbit. Dwarf planets can not because of their weaker gravity Information from

47 Background info on Dwarf Planets There are currently three official dwarf planets. Pluto, formerly the smallest of the nine "traditional" planets, was demoted to dwarf planet status. Ceres, the largest asteroid in the main asteroid belt between Mars and Jupiter, was also declared a dwarf planet. The third and final (for now!) dwarf planet is Eris, an icy body on the edge of our Solar System that was discovered recently in Eris was temporarily labeled 2003 UB313 when it was first discovered, and given the nickname "Xena", before astronomers settled on the official name of Eris.PlutoCeresEris Text from

48 Background info on Dwarf Planets continued What's the difference between regular planets and dwarf planets? As you might guess, it's partly an issue of size, with dwarf planets being smaller. But just how big does a planet need to be to become a full-fledged planet instead of a dwarf? You might think the minimum size requirement is arbitrary, but the size cutoff is actually based on other properties of the object and its history in the Solar System. Both planets and dwarf planets orbit the Sun, not other planets (in which case we call them moons). Both must be large enough that their own gravity pulls them into the shapes of spheres; this rules out numerous smaller bodies like most asteroids, many of which have irregular shapes. Planets clear smaller objects out of their orbits by sucking the small bodies into themselves or flinging them out of orbit. Dwarf planets, with their weaker gravities, are unable to clear out their orbits.Though there are just three dwarf planets now, their number is expected to grow. Scientists estimate there may be 70 dwarf planets amongst outer solar system objects that have been discovered already. Since we don't know the actual sizes or shapes of many of the objects we've found (because they are so far away), we can't yet determine whether they are actually dwarf planets or not. More observations and better telescopes will help us determine which other objects are dwarf planets. Astronomers speculate that there may be 200 or so dwarf planets out through the distance of the Kuiper Belt, an icy band of frozen planetoids on the edge of our Solar System.regular planetsorbitSunirregular shapes orbitsKuiper Belt Text from

49 Additional Sources nets/dwarf_planets.htmlhttp:// nets/dwarf_planets.html