The Solar System

Solar System

• the sun and all things orbiting around it, including the eight major planets, their satellites, and all the smaller pieces such as asteroids, meteoroids, and comets

Image taken from: http://asm.arc.nasa.gov/Gallery/images/generic/LG_Capableofeverything.jpg

Not to scale

Formation of the Solar System

Formed around 4.6 billion years ago

Solar Nebula Huge cloud of gas and dust that collapsed into a flattened disk

DiskSun formed at the center of the disk

while other objects (planets, moons, etc.) formed from the whirling material of the

disk

Solar SystemMuch of the material was cleared away.

The Sun, planets, and other objects remained

Images taken from: http://astronomyonline.org/SolarSystem/SolarSystemFormation.asp

Planet

• derived from a Greek word that means “wanderer”

• a major object which orbits around a star

• in our solar system, there are eight such objects which are traditionally called “planets”

Orbit• the path of an object in space as it travels around

another object• planets orbit around the sun in an elliptical (flattened

circle or oval) path; proposed by Johannes Kepler Kepler’s 1st Law

• due to the gravitational attraction, a planet’s (or other object’s) speed increases as it approaches the sun

• Planetary Motion

What do you think is the relationship between a planet’s orbit and a “year?”

The Earth animation

is not rotating in the correct direction;it should

be rotating from west

to east

Not to scale

Mass vs. WeightMass

• a measure of how much matter an object is made of

• does not change, regardless of where something or someone is

Weight

• the force of gravity on an object

• equal to the mass of the body times the local acceleration of gravity

http://www.exploratorium.edu/ronh/weight/index.html

Why do you think

the person’s weight is

less on the moon?

Mass = 59 kg Mass = 59 kg

Weight = 579 N Weight = 96 N

The Earth animation

is not rotating in the correct direction;it should

be rotating from west

to east

Rotation vs. RevolutionRotation

• the movement or path of the earth or a heavenly body turning on its axis

• equivalent to one “day”• Earth rotates at a speed of

around 1,670 km/hr or 1000 mi/hr

Revolution

• the motion of one body around another, such as Earth orbiting around the sun

• also known as an orbital period• equivalent to one “year”• Earth revolves at a speed of

around 107,000 km/hr or 67,000 mi/hr

Tips for remembering:rotation occurs in one day; day has three letters and rotation has three syllables

revolution occurs in one year; year has four letters and revolution has four syllables

Sun

The Earth animation

is not rotating in the correct direction;it should

be rotating from west

to east

Factors Influencing Planetary Characteristics

Tectonicsthe process of change in a crust due to the motion of hot material underneath

Volcanismthe process of molten

material moving from a space body’s hot interior

onto its surface

Weathering and ErosionWeathering - the breaking down of rocks into smaller pieces;

mostly caused by movements of water, wind, and ice

Erosion – the process in which sediment is picked up and moved from one place to another

Impact Crateringa process that occurs when a round pit is left behind on the

surface of a planet or other body in space

after a smaller object strikes the surface

Animation taken from: http://www.odsn.de/odsn/services/paleomap/animation.htm l

The Earth animation

is not rotating in the correct direction;it should

be rotating from west

to east

Atmosphere• the outer layer of gases of

a large body in space, such as a planet or star

• usually composed of layers• Greenhouse Effect

– the trapping of radiant energy by the gases (CO2, CH4, H2O, among others) that compose the atmosphere

– planetary conditions would be very different without it (i.e. – the Earth’s temperature would be 60oF cooler we would not survive)

Radiant energy from

the sun

What do you notice about the amount of energy entering the atmosphere, compared to the amount leaving?

The Earth animation

is not rotating in the correct direction;it should

be rotating from west

to east

Image taken from:

http://www.ucar.edu/learn/1_1_1.htm

Planet Classifications

• Terrestrial Planets(inner planets)

– Mercury, Venus, Earth, Mars– closest to the sun– composed primarily of rock

and metal– have deep atmospheres

(except Mercury), solid surfaces, no rings, & few satellites

• Gas Planets(outer planets)

– Jupiter, Saturn, Uranus, Neptune

– composed primarily of hydrogen & helium

– have deep atmospheres, rings, & many satellites