The Solar System

Not pictured, the dwarf planet Ceres Neptune Uranus Saturn Not pictured The dwarf planet Eris Jupiter Mars Earth Venus Mercury Not pictured, the dwarf planet Ceres Image from http://www.nineplanets.org/gif/NinePlanets.jpg

Image from http://www.nineplanets.org/gif/NinePlanets.jpg

Another perspective Another perspective Renamed Eris Image from http://media.skyandtelescope.com/images/TwelvePlanets_l.jpg

The Inner Planets Mercury Venus Earth Mars

Humans Needs? Oxygen (Not 100%) Water Favorable Temperature Daily sunlight for photosynthesis Favorable Atmosphere conditions (little CO2, no narcotic gases(argon), total pressure around 1atm)

Characteristics of the Inner Planets Very similar to each other small rocky surfaces. Dense. NO rings “Terrestrial planets” because they resemble Earth, “terra-” means “Earth”

Mercury Size- about 38% of Earth’s diameter =4878 km Distance from sun- about 39% of Earth’s distance=58,000,000 km Surface- thin, hard rocky surface with plains and craters Atmosphere- thin with sodium and gases

Mercury(cont’d) Can’t support life (no water or oxygen, hot temps) Moons- none Rotation- 59 Earth days Revolution- 0.24 Earth years Daytime(sunlit side) temperature 430ºC Nighttime(shaded side) temperature -190ºC

Mercury

Venus 95% of Earth’s diameter=12,104 km Distance from sun- about 2/3 of Earth’s=108,000,000 km from sun Surface- rocks similar to Earth Has volcanoes with lava flows

Venus (cont’d) Atmosphere- thick Mostly carbon dioxide (greenhouse effect is strong) Clouds partly sulfuric acid Atmospheric pressure is 90 times heavier than Earth’s and would crush a human No water Harsh temperatures and atmosphere

Venus (cont’d) Sometimes called “Earth’s twin” Retrograde rotation- rotates “backward” from east to west (opposite of Earth) Rotation=8 Earth months Revolution=7.5 Earth months Moons- None

Venus

Earth 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

Earth Rotation takes 24 hours Revolution takes 365.25 days Earth has one moon

Earth

Mars Size- 53% of Earth’s diameter, it is 6794 km Distance from Sun- about 1.5 times distance of Earth 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

Mars Atmosphere- Very thin, Thin clouds Mostly carbon dioxide 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

Mars continued Rotation- 1.03 Earth days Revolution- 1.9 Earth years Mars has largest volcano in solar system, called Olympus Mons Moons- 2

Mars

The Outer Planets Jupiter Saturn Uranus Neptune Pluto (a dwarf Planet)

Characteristics of The Outer Planets Jupiter, Saturn, Uranus, Neptune and the dwarf planets Pluto and Eris Jupiter, Saturn, Uranus, and Neptune are called “Gas Giants” Larger than Earth Don’t have solid surfaces Pluto and Eris are small and rocky, like the terrestrial planets.

Characteristics of Gas Giants Don’t have well-defined surfaces Deep atmospheres about 75% hydrogen, 24% helium, and 1% other elements Solid cores of rock, ice, frozen carbon dioxide and other compounds

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 Deep atmosphere of about 86 % hydrogen,14 % helium, and tiny amounts of other substances.

Jupiter continued Lacks water, oxygen and moderate temperatures. Largest planet in solar system with 300 times the mass of Earth Rotation- 0.41 Earth days (fastest) Revolution- 29 Earth years

Jupiter continued Moons- 67 Has dark rings Great Red Spot is storm on Jupiter, twice as big as Earth

Jupiter

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 Syruplike mixture of helium and hydrogen Atmosphere of gaseous helium and hydrogen

Saturn continued Lacks water, oxygen, and moderate temperatures Second largest planet in solar system Rotation- 0.43 Earth days Revolution- 29 Earth years

Saturn continued Moons- 62 Low density planet, could float in water Prominent rings- mostly chunks of ice and rocks

Saturn

Uranus 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

Uranus continued Surface consists of blue-green clouds made up of tiny ice crystals of methane, and rock. Atmosphere is about 83% hydrogen, 15% helium and 2% methane.

Uranus continued Lacks water, oxygen, and moderate temperatures needed to support life, NO known life Rotation- 0.72 Earth days, is retrograde rotation like Venus, and rotates on side Revolution- 84 Earth years Moons-27 Rings- 13 dark rings

Uranus

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 Composition: Ice and Silicates (rock) with about 15% hydrogen, some water, and a little helium

Neptune continued Atmosphere:hydrogen and helium with a small amount of methane. Lacks significant water, oxygen, and moderate temperatures

Neptune continued Rotation- 0.67 Earth days Revolution- 165 Earth years Visible clouds in atmosphere Moons- 13 Rings-5

Neptune

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

Pluto continued 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

Pluto

The Dwarf Planets Ceres- new dwarf planet, it was classified as the largest asteroid in the Asteroid Belt (it is between Mars & Jupiter). 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.

The Dwarf Planets and their Moons

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. Pluto doesn’t dominate it’s orbit due to it’s small mass. Neptune crosses into it’s orbit.

Meteorite vs. Meteoroid Meteoroid = while in space a meteorite is called a meteoroid Meteorite = a small rock or rocky grain that strikes Earth’s surface

Meteor Sometimes called a “Shooting Star” When a meteorite enters Earth’s atmosphere, friction causes them to burn up, producing a streak of light

Where do they come from? How big are they? Pieces of rock that broke off other objects Sizes range from as small as a pebble or as big as a huge boulder

Are they dangerous? Most meteoroids disintegrate before reaching the earth by burning up in Earth’s atmosphere Some leave a trail that lasts several minutes Meteoroids that reach the earth are called meteorites. Large ones can cause damage

Flagstaff, Arizona 49,000 years ago Meteorite about 150 feet in diameter Weighed 650 pounds Energy = 2.5 million tons of dynamite 4000 feet wide, 650 feet deep Still visible today Barringer Meteorite Crater

What’s a “Meteor Shower”? Icy surface of comets heat up as they get closer to the sun. Debris particles are released. Occur when Earth passes through the tail or debris of a comet

Comets Bodies in space made up of ice, dust, small gritty particles Sometimes called “dirty snowballs” When close to the sun, ice vaporizes, producing a spectacular streak of gas, referred to as a “tail” Many in a regular orbit around the sun

Comets

Where do comets come from? Many ordinate in a region called the Oort cloud beyond Pluto Others originate in the Kuiper Belt beyond Neptune

Asteroids An irregularly shaped rocky object in space (like a space potato) May be the shattered remains of objects left over from the time when the planets were formed

How big are asteroids? Larger than meteoroids Size ranges from 10 feet across to bigger than a mountain

Asteroids Most are in a band that orbit the sun between Mars and Jupiter (Asteroid Belt) At least 1000 asteroids orbit outside of the Asteroid Belt – these could be a danger to Earth Asteroids that cross Earth’s orbit are called Near-Earth Asteroids or NEAs NEA / Earth collision not likely But if it did, the affect of the impact would depend on the size of the asteroid

Large Asteroid hits Earth 65 Million Years Ago Catastrophic Collision Asteroid 6 to 12 miles in diameter Near the Yucatan Peninsula in the Gulf of Mexico

Large Asteroid hits Earth 65 Million Years Ago Collision produced an explosion = 100 trillion tons of dynamite Gouged out a crater about 60 miles in diameter How would an event like this affect Earth?

What do Scientists Think Happened? Forests were wiped clean for a distance of 300 to 600 miles in all directions 300 foot wave struck the coast of Texas Powerful Earthquakes Landslides destroyed long stretches of coastline Debris would cover large parts of North America Poisonous gases and dust spread over most of the Earth,

What do Scientists Think Happened Sunlight was blocked for many months Temperatures plummeted to the freezing point Not enough sunlight for photosynthesis Plants died . . . Animals died Many animals became extinct (including many types of dinosaurs)

The Rise and Fall of Life on Earth Dip around 65 Million years ago?