We continue to Learn a lot about the

Solar System by using Space

Exploration

CHAPTER 11

Section 11.1 The Sun page 390

-Average sized star

-Millions of km away

-300,000 more massive then

Earth, 99% of all mass in our

solar system

-Approx. 5 billon Years old with

5 billion more to go!

The Huge size of the sun causes

pressure to build up at the center of

the sun as gravity pulls the mass

inward… Thermonuclear Reactions turn

H (hydrogen) He (helium) giving

off Heat, Light and UV radiation in the

process

H He

Heat, Light and UV radiation

Pressure

Solar Radiation - E (energy) Emitted

from the sun in the form of

Electromagnetic Radiation

… E that is carried or radiated in

the form of waves that range in

length, ex. Microwaves, radio

waves, UV waves

The Earth is located in the “Goldilocks Zone”,

not too hot, not too cold, just right!

SUNSPOTS – dark patches of slightly

cooler (3500°C) surface areas on the

sun, they increase and decrease in

number on an 11-yr cycle. They may be

related to changes in the Earth’s

climate .

SOLAR FLARES – eruptions of

gas on the suns surface – can

last a few hours, temperatures

increase up to 11,000,000°C

Creates Solar Winds

Solar Wind page 393

Hot E bubbles “pop” on the surface of the sun and send

high E particles rushing past Earth. Earth is protected

from this solar wind by its magnetic field. Some of the

particles enter the Earth’s atmosphere at the poles

where they collide with the gas in the atmosphere to

create Auroras (Northern/Southern lights) page 394.

Some solar winds can disturb Earth’s

magnetic field and disable satellites,

knock out power lines, and expose

astronauts to high levels of radiation

Section 11.2 page 398

Characteristics of the Celestial Bodies

of the Solar System

The Planets

To be a planet you must…

… orbit 1 or more stars

… be large enough so its gravity

holds it in place

… be the only body in its orbital

path

Astronomical Units (AU)

Used to measure distances in space

1 AU = 150 million km

(the distance from the Earth to the Sun)

1 AU

5.27 AU

Activity 11-2A:

Terrestrial and Jovian Planets

Listen to the information contained in the video on the

planets and complete the table on page 402!

Mnemonic Device to Remember the order of the Planets???

Mercury, Venus, Earth, Mars, Jupiter,

Saturn, Uranus and Neptune

Criteria Terrestrial

Planets (Inner)

Jovian Planets

(Outer)

Size Small (all Earth size

or smaller)

Large (4 to 11 times

greater than Earth)

Motion Slow spinning, small

orbits

Faster spinning,

larger orbits

Composition Solid and rocky Gaseous

Distance from

Sun

Closer Further away

Temperature Warmer, but

temperatures vary

Colder, but

temperatures vary

Density Greater Lesser

PLUTO

Now considered Dwarf Planet

– a celestial body orbiting the Sun that is

generally smaller than a planet but massive

enough for its own gravity to give it a round

shape. However they are not strong enough

to clear their orbit of debris

There are many other “dwarf planets” some

are bigger and some like Pluto have moons

A Comparison of 3 dwarf planets and

Earth, notice some have moons and some

don’t

COMETS “dirty snowballs” composed

of ice, rock and gas

Originate from the KuiperBelt and Oort Cloud

They travel in long elliptical orbits around the sun which are affected by the gravitational pulls of other planets

It has a long dust tail as sunlight starts to melt the ice, these can stretch millions of km

Most famous Halley’s comet which is visableevery 76 years or so

Periodicity of Comets:

"Period" is the amount of time it takes an object in

orbit to return to its starting location.

Comets travel

in short and

long periods

around the

sun in elliptical

orbits

The elliptical orbit of Halley’s Comet

ASTEROIDS

Small bodies believed to be the leftover remains of the

formation of the Solar System

Mostly found in an asteroid belt between Mars and

Jupiter

They have irregular shapes

Range in size from a

grain of sand up to 1000km

An asteroid up

to 1 km would devastate Earth

METEORS

Meteoroid – a rocky chunk,

broken off an asteroid or

planet, which floats

through space

Meteor – a meteoroid that

burns up as it passes

through Earths

atmosphere, seen as a

shooting star

Meteorite – a meteoroid

that does not burn up fully

in the Earths atmosphere

and hits the Earths surface

Deep Impact Sites

A place where a relatively small object (meteorite) has

collided with a larger object (planet)

Produces a fairly circular depression in the surface of

the larger object referred to as an impact crater