Our Solar System

The Sun – our very own star• The Sun is the center of our solar system

• The word “solar” means “of the sun”

• Our sun is a medium-sized star

• Our sun is medium-hot, and yellow

The Inner Planets

Spinning Planets

• Period of Rotation: amount of time that an object takes to rotate once. (1 Day)

• Period of Revolution: time it takes an object to revolve around the sun once. (1 year)

http://www.youtube.com/watch?v=97Ob0xR0Ut8&feature=related

Mercury• On Mercury you weigh only 38%

of what you weigh on Earth.• Fastest orbiting planet • Planet nearest to the sun

• One side of the planet can be 800 degrees Fahrenheit when the other can be -280 degree Fahrenheit at the same time.

• Orbit Period 88 days• Rotation Period 59 days

Venus• On Venus you weigh only 91% of what you weigh on

Earth.

• Venus has 90 times the pressure of Earth and it’s the hottest planet.

• Venus has volcanoes like Earth

• Rotates in the opposite direction of Earth.

• One time there were oceans before they boiled away.

• Orbit Period 224 days

• Rotation Period 242 days

Earth• 23 hours and 56 min=1 Earth day (rotation)

• 365 days =1 Earth year (revolution)

• Earth is warm enough to keep most of its water from freezing and cold enough to keep it’s water from boiling

• Temperature is between –13 degrees Celsius and 37 degrees Celsius

Mars

• Air Pressure on Mars is the same as 30 km above the Earth’s surface

• Mars is in the form of ice.

• Evidence that water was there at one time

• Volcanic history like Earth.

• It has the tallest mount of the planets (Olympus Mons) 3x’s size of Mt. Everest.

• Orbital Period 687 days

• Rotation Period 24. 6 hours

Outer Planets

Jupiter

• Largest planet in the Solar System

• Has a Great Red Spot from a storm system that is more than 400 years old

• Pressure is so great it would crush a spaceship.

• Orbit Period 12 years

• 9 hours and 54 min=1 Jupiter day (shortest day)

Saturn

• 2nd Largest planet in the Solar System

• 95 times more massive than earth.

• Saturn has the largest rings of any planet, the rings are made of icy particles.

• Most moons of any planets ( 47 known)

• Orbit Period 12 years

• Rotation Period 10 hours

Uranus

• Discovered in 1781

• Uranus appears blue-green in color

• It’s axis of rotation is tilted 90 degrees

• Moons are named after Shakespearean plays and formed from other broken moons.

• Orbit Period 84 years

• Rotation Period 17 hours

Neptune

• Discovered in 1846• The atmosphere appears blue and is

marked by large dark blue storms• Neptune has visual belts of clouds• It has a system of 5 rings and at least 13

moons• Orbit Period 165 years • Rotation Period 16 hours

Pluto

• Discovered 1930

• Mystery Planet

• Farthest from the sun

• Recently changed from a being considered a planet to a dwarf planet.

• Orbit Period 248 years

• Rotation Period 6.4 days

21st Century Solar System

If you traveled on a shuttle that’s going 28,000 mph it would

take…

• Mercury 52d

• Venus 100d

• Mars 210d

• Jupiter 1.9yr

• Saturn 3.6yr

• Uranus 7.3yr

• Neptune 11.4yr

• Pluto 15.1yr

Dwarf Planets

• A dwarf planet is a celestial body massive enough to be spherical, in orbit around the Sun, which are not satellites. The crucial factor dividing a planet from a dwarf planet is that a planet must have succeeded in clearing the area of its orbit from debris and other objects, whereas a dwarf planet has not.

Dwarf Planets

Kuiper Belt

• Class of icy bodies orbiting beyond Neptune.– Found only in the outer Solar System (>30AU)– Densities of 1.2 to 2 g/cc (mostly ices)

• Examples:– Pluto & Eris (icy dwarf planets)– Kuiper Belt Objects (30-50AU)– Charon, Pluto’s large moon– Sedna & Quaor: distant large icy bodies

Kuiper Belt

The Leftovers (small bodies)

• Asteroids:– Made of rock & metal (density 2-3 g/cc)– Sizes: Few 100km to large boulders– Most are found in the Main Belt (2.1-3.2 AU)

• Meteoroids:– Bits of rock and metal– Sizes: grains of sand to boulders

• Comets:– Composite rock & ice “dirty snowballs”– Long tails of gas & dust are swept off them when

they pass near the Sun.

Meteoroid, Meteorite and Meteor

• A meteoroid is a small rock or particle of debris in our solar system. They range in size from dust to around 10 metres in diameter (larger objects are usually referred to as asteroids).

• A meteoroid that burns up as it passes through the Earth’s atmosphere is known as a meteor. If you’ve ever looked up at the sky at night and seen a streak of light or ‘shooting star’ what you are actually seeing is a meteor.

• A meteoroid that survives falling through the Earth’s atmosphere and colliding with the Earth’s surface is known as a meteorite.