Chapter 27

The Solar System

Standards 1a. Students know how the differences and similarities among the sun, the terrestrial planets, and the gas planets may have been established during the formation of the solar system.1b. Students know the evidence from Earth and moon rocks indicates that the solar system was formed from a nebular cloud of dust and gas approx. 4.6 billion years ago.1c. Students know the evidence from geological studies of Earth and other planets suggest that the early Earth was very different from Earth today.

Objective 1 Explain nebular hypothesis.Objective 2 Describe the land, atmosphere,

and oceans of early Earth.

Objective 3 Identify the basic characteristics of the inner planets.

Objective 4 Identify the basic characteristics of the outer planets.

Assessment Ch.27 TestReview Daily Bellwork, Science Starters

Vocabulary

Create flashcards for the following key terms. They begin on page 685.• Solar System• Planet• Solar Nebula• Terrestrial Planet• Gas Giant• Kuiper Belt

INTERACTIVE The Planets Song

Create a Mnemonic to Remember the order of the planets…Example: MyVery EagerMotherJust Served UsNoodles

Solar System Song

Brainpop Solar System

Formation of the Solar System

Nebular Hypothesis• The sun and the planets formed at the same

time from a rotating cloud of dust and gas called a NEBULA.

• Gravity pulled the gas and dust closer and closer together creating heat and density.

• When the temp. became hot enough (10 million degrees) a star was born—our sun.

• 99% of all the matter in the nebula is in the sun.

Nebular Hypothesis Cont.

• While the sun was forming in the center, PLANETESIMALS were forming in the outer regions.

• PLANETESIMALS were small bodies or ‘chunks’ of debris that collided with other planetesimals which eventually (through gravity and collisions) formed larger bodies called PROTOPLANETS.

• PROTOPLANETS became PLANETS as they got larger.

Formation of the Solar System Video Clip

Formation of the Inner Planets

• How the new planets developed depended on their distance from the Sun.

• Those near the sun (Mercury, Venus, Earth, and Mars) contained heavy elements (iron and nickel) and they lost most of their gases (gravity was not strong enough to hold them in).

• Denser material sank to center of planets and layers formed.

• Inner planets are closest to the sun, dense, and relatively small.

Formation of the Outer Planets

• Jupiter, Saturn, Uranus, and Neptune were far from the sun and formed in cold areas where they did not lose their gases (helium and hydrogen) or their ices ( water, methane ice, ammonia ice).

• Ices would later melt and the outer planets are composed mainly of liquids and gases.

Ancient Earth• Originally VERY hot• Denser materials (iron) sank to center, formed 3 distinct

layers (core, mantle, crust)• Early atmosphere=lots of volcanoes outgassing Nitrogen,

water vapor, ammonia, methane, argon, sulfur dioxide, carbon dioxide

• NO OXYGEN in the early atmosphere• Early organisms began to photosynthesize which led to the

production of Oxygen…2 billion years ago Oxygen level significantly increased and our atmosphere became like it is today.

Earth’s formation Clips

Earth’s formation Clips

Inner Planets Today

• “Terrestrial” planets—made of solid rock with metallic cores

• Many impact meteor craters

Mercury

• Closest to the sun• Rotates on its axis every 59 days• Heavily cratered• Cliffs• Little atmosphere causes high temps in

daylight (472 degrees C) and low temps in night (-173 degrees C)

Mercury

Venus

• 2nd planet from the sun• Slow rotation…once every 243 days• Earth’s ‘twin’…same size, mass, density• Atmosphere: 90 times the pressure of Earth,

96% carbon dioxide• The CO2 creates a huge Greenhouse Effect,

creating temps of 464 degrees Celsius.• Hottest planet in solar system

Venus

• Rocky surface, granite and basalt• Mountains, volcanoes, lava plains, sand dunes

Venus

Mars

• 4th planet from the sun• Rotates every 24 hours, 37 min, revolves around

sun in 687 days• Axis tilts like Earth, has seasons• Large volcanoes, seismic activity (marsquakes)• Once had lots of water…now only in polar ice caps,

possibly underground• Very thin atmosphere…temps range from 20 to

minus 130 degrees Celsius

Mars

Inner Planets Video

Outer Planets Today

• Separated from inner planets by the asteroid belt.

• Also known as the Gas Giants• Their large size led to greater gravity which let

them keep all their gases (unlike the inner planets) and they have thick atmospheres

• Cores are rock and metal• All four gas giants have ring systems

Jupiter• 5th planet from the sun• Largest Planet• At least 60 moons, several thin rings• Atmosphere= 92% hydrogen and helium• Temp. is -160 degrees in the atmosphere• Lightning storms and thunderstorms (larger than on Earth)• Great Red Spot = a giant (2x the size of planet Earth),

rotating storm similar to a hurricane• Jupiter’s interior is very hot…30,000 degrees! Mostly a

liquid planet

Jupiter

Saturn

• 6th planet from the sun• Orbits the sun ever 29.5 years• Very cold planet due to its distance from the sun (-

176 degrees)• 30+moons• Mostly hydrogen and helium with a rocky core• Least dense planet in the solar system• Complex ring system from comets and other space

debris

Saturn

Uranus• 7th planet from the sun• 3rd largest• At least 24 moons and 11 thin rings• Revolves around the sun in 84 years• Instead of rotating perpendicular to its orbit, it rotates

parallel every 17 hours• Atmosphere is mostly hydrogen and helium and

methane. Blue color comes from methane gas• Cold planet…-214 degrees, but could be higher under all

the clouds

Uranus

Neptune

• 8th planet from the sun, similar to Uranus in size and mass

• 164 years to revolve around sun, rotates in 16 hours

• Atmosphere—Hydrogen, helium, methane• Strongest winds in the solar system (1000

km/h)

Neptune

The Outer Planets Video

Solar System Song

INTERACTIVE/Assessment

Compare and Contrast the Inner and Outer Planets…

Inner Outer

INTERACTIVE/Assessment

Using your Venn Diagram as a guide, write an essay comparing Inner and outer planets.--Intro Paragraph--Inner--OuterMinimum of 200 words

INTERACTIVE/AssessmentIn groups you will create a poster for your planet. You need to include:• Drawing of planet• 7 or more facts about your planet

– Where in the solar system is it?– How big?– Moons?– Rings?– Atmosphere?– Rotates?– Revolves?– Temperature?– Other