Our Solar SystemNotes

3-26-12

Astronomical Unit• (AU)

• The average distance between the Earth and the sun

• 149,600,000 km

• Light travels 300,000 km per second

• Light takes 8.3 minutes to reach Earth from the Sun.

Rotation• The spin of an object in space.

• Earth rotates every 24 hours.

Orbit

The path an object takes around the Sun.

RevolutionThe motion of traveling around another object

in space.

• Earth revolves around the Sun once a year

(365 days)

Who am I?

• Has inspired mythological stories in cultures around the world, including those of the ancient Egyptians, the Aztecs of Mexico, Native American tribes of North America and Canada, the Chinese, and many others.

SUN

• Closest star to Earth

• A hot ball of burning gas

• Without the Sun’s intense heat and energy there would be no life on Earth.

• Has multiple layers

• The part of the Sun that we can see is 11,000 degrees F (6,100 degrees C).

• It gets hotter as you go deeper.

So what exactly is a planet?

A "planet" is a body that

A. is in orbit around the Sun

B. has mass; nearly round shape

C. has cleared the neighborhood around its orbit

The Inner Planets

Who am I?Hint: Not the moon

MERCURY

• Planet closest to Sun

• No moons• Mercury completes a trip

around the Sun every 88 days

• Because it is so close to the Sun, temperatures on its surface can reach a scorching 467 degrees Celsius

• because the planet has hardly any atmosphere to keep it warm, nighttime temperatures can drop to a frigid -170 degrees Celsius

Who am I?

VENUS• 2nd closest to the Sun

• Covered by thick, quickly spinning clouds that trap surface heat.

• HOTTEST PLANET!• No Moons

• Revolves around the Sun every 224 days

Unknown

Who am I?

EARTH• Only planet known to support life

• 1 moon- Luna

• Air, water, land, and life - including humans

Who am I?

MARS•The RED planet•small , rocky body once thought to be very Earth-like

• It has polar ice caps that grow and shrink with the change of seasons

• 2 Moons- Phobos & Deimos

Revolves around the Sun every 689 days

• Earth has plates that move and slide past each other

• Martian tectonics seem to be vertical, with hot lava pushing upwards through the crust to the surface. Periodically, great dust storms engulf the entire planet

The Outer Planets

Who am I?

JUPITER• Most massive planet in our solar system

• Made of mostly ammonia, hydrogen, helium

• Takes 11 Earth years for Jupiter to complete 1 revolution

• The Great Red Spot, a giant spinning storm, has been observed for more than 300 years.

• 4 major moons- Io, Europa, Ganymede, Callisto

• HOW MANY MOONS TOTAL?

• 62 Moons total!!!

Who am I?

SATURN• Made mostly of hydrogen and helium and still getting larger

• Saturn’s rings extend thousands of kilometers from the planet

•Saturn's rings are made mostly of ice and rock

•52 Moons• Largest moon is Titan

Who am I?

URANUS• Uranus was discovered in 1781

• 84 Earth years to complete one orbit

• Made mostly of hydrogen and helium

• Gets blue-green color from methane gas

Tipped on its side and has seasons that last over 20 years

• 27 Moons

• Most moons named after Greek mythology, but these moons named after William Shakespeare characters

Who am I?

NEPTUNE• Neptune orbits the Sun

once every 165 years (2 BILLION MILES AWAY)

• It is invisible to the naked eye because of its extreme distance from Earth

Has a storm called the “Great Dark Spot”, but the storm is smaller than the

one on Jupiter.

•Blue color is the result of methane

in the atmosphere

•13 known moons

Pluto• Downgraded to a dwarf

planet in 2006

• 3 moons – Hydra, Nix, Charon

• No spacecraft have visited Pluto

Who am I?

Romeo and Juliet

O, Swear not by the moon,

The inconstant moon,

That monthly changes in her circled orb,

Lest that thy love prove likewise variable.

Satellite

• Natural or artificial bodies that revolve around more massive bodies such as planets.

• Mercury and Venus have no natural satellites called moons.

What am I?

Comet

•Small body of ice, rock, and cosmic

dust loosely packed together

•Formed in outer solar system

•When passing close to the sun the ice gets heated and forms a long tail.

What am I?

Asteroid• Small, rocky bodies that

revolve around the Sun.

• Range in size from a few meters to more than 900

km in diameter

•They revolve in the asteroid belt

between Mars and Jupiter

What am I?

Meteor

• Much smaller than asteroids

• Smaller, rocky bodies that revolve around the

sun

• Probably pieces of asteroids

• It is called a meteorite when it hits Earth