Lecture 2: The Solar System 1)  WileyPLUS (online) – registration? homework? 2)  Final Exam scheduled Tuesday, December 15 (12-2)

3)  iClickers – assigned on Tuesday

4)  Big Island Field Trip

Fall 2015 Big Island Field Trip – Everyone invited

Dates: September 25-27 Sign-up with GG Dept Secretary - POST 701 Cost $150 + your own round-trip plane ticket

Cash or check payable to “Geology Club”

This is a weekend of hiking, picnicking and learning about the worlds most active volcano at “Volcano National Park”. Hikes include: Thurston Lava Tube (0.25 mi); Kilauea Iki (4 mi); Puu Loa Petroglyphs (2 mi); Mauna Ulu summit crater (3.2 mi); Sulphur Banks (0.5 mi), Big island Candy Company; and Rainbow Falls, Hilo.

Hike Volcano National Park, stay at Kilauea Military Camp Van transportation, lodging, and food provided EXTRA CREDIT, 3%

1.  What we’ll learn today:"

2.  1. Describe the solar nebula hypothesis"3.  "4.  2. Understand the Sun and how it works"

5.  3. State the ways that Mercury, Venus, and Mars are different from Earth"

6.  4. Describe each of the gas giants"

7.  5. Define a dwarf planet"

Learning Objectives (LO)

The Universe

•  100,000 light years across

•  400 billion stars

•  Our location is not unusual

Our Galaxy: The Milky Way

Formation of our Solar System

•  Steven Hawking created this video on the formation of the Solar system

https://www.youtube.com/watch?v=Uhy1fucSRQI

A nebula is a cloud of gas and dust

made by an exploding star.

•  Stars release energy and build elements through nuclear fusion.

•  Nuclear fusion creates new elements.

•  Stars “burn” hydrogen, becoming brighter.

•  Eventually, stars become Red Giants and explode. Butterfly Nebula

3,800 light-years away

Solar Nebula Hypothesis

•  Our Sun and other objects originated from a solar nebula.

Crab Nebula

•  The Solar Nebula Hypothesis – ours began about 5 billion years ago

2. The nebula collapses and begins to rotate

4. Gravity pulls planetesimals together to form planets

1. Initial cloud of interstellar gas (the solar nebula)

3. Accretion of cooler outer disk into planetesimals

How Did the Solar System Form?

•  Collisions of particles of ice, gas, and dust that grew into larger planetary objects

•  ~5 to 4.6 billion yrs ago

Planetesimal Accretion

Rocks and metals (heavy) – remained near the Sun

Gases (light) Water, methane, ammonia Helium, hydrogen - expelled to outer solar system

Next: A “solar wind” of charged particles from the Sun blew gases (volatiles) toward outer solar system

Solar Wind “Push”

Our Solar System Consists Of: •  1 unordinary star •  8 classical planets •  5 dwarf planets •  240+ known satellites (moons) •  Millions of comets and asteroids •  Countless particles; and interplanetary space

Earth, the Sun, and other objects in the Solar System originated at the same time from the same source and have

evolved in varying ways since then

Our Sun : A Massive Hydrogen Bomb Held Together by Gravity

Our Sun • Solar core is site of

nuclear fusion.

• H is converted to He, which has less mass.

• Mass differential is expelled as energy (light and heat).

• The Sun is getting “lighter” through time.

• The Sun has enough fuel to last another 4 to 5 billion years.

Dynamic Equilibrium

•  Gas exerts pressure outward, balanced by force of gravity inward

  Intense pressures fuse Hydrogen (H) into Helium (He)

  Nuclear explosion held together by gravity

Nuclear Fusion

•  700 million tons of H are converted to He every second   Energy is released as radiation – takes 1 million years to exit the sun (!)

  Sunlight takes 8 min.to reach Earth

The Expected Future of Our Sun

The Sun is 4.6 billion years old

At about 9 billion years: The sun runs out of Hydrogen fuel It begins to burn Helium It grows MUCH bigger to become a Red Giant

At about 11 billion years: collapse into White Dwarf

1 AU 2 AU 3 AU 4 AU 5 AU

•  Origin of the Earth – 4.6 billion years ago

Jupiter

1 AU 2 AU 3 AU 4 AU 5 AU SUN

•  1 AU = Astronomical Unit

Earth

= distance from Earth to the Sun

= 1.5 x 108 km

1 AU = Astronomical Unit

= 1.5 x 108 km

100,000 m or 100 km

Jupiter

1 AU 2 AU 3 AU 4 AU 5 AU SUN

•  1 Rearth = Radius of the Earth

= 6378 km

Earth

1x Rearth 11x Rearth

Earth-Sized: Inner planets (+ Pluto)

Outer planets are much bigger

But the Sun is Far Larger

Radius of the Sun

= 700,000 km

Many Stars Are Much Bigger Than the Sun

Some Stars Are Truly Gargantuous

Betelgeuse

Mercury Venus Earth Mars

Terrestrial Planets

Main components: O, Fe, Si, Mg, Ca, K, Na, Al

Terrestrial planets are small and rocky, with thin atmospheres, silicate & metallic shells.

Jupiter Saturn

Uranus Neptune

Gas Giant planets are massive with thick atmospheres. Main components: He, H, CO2, H2O, N2, NH3, CH4

Gas Giant Planets

Mercury •  Smallest planet •  Silicate (SiO2) shell •  Probable molten iron core •  Extreme temps: 227oC -137oC

2-mile high scarp

  Slightly smaller than Earth   Spins slowly and backward   Thick CO2 atmosphere   Runaway greenhouse: 447°C   Recent volcanism   Active mantle interior

lava flows

Venus

Images From the Surface of Venus Venera-13 (1982)

Earth   Thin atmosphere   Moderate temperatures   Liquid water, life!   Active tectonics & volcanism   One large moon

The Birth of Earth’s Moon

=

•  Collision with a another planet-sized object

Moon Formation Event

https://www.youtube.com/watch?v=xbdxp0fa1hA

Moon Formation Event Collision with a another planet-sized object

  Thin CO2 atmosphere   Liquid water in the past: oceans, stream beds, beaches   Recent volcanism, today?

Mars

- 700 km diameter

- 27 km high

- largest volcano in Solar System Entire Big Island

Big Volcanoes on Mars

Olympus Mons:

Olympus Mons vs. Hawaii

- volume ~100 x Mauna Loa

Images from Mars

Stream beds?

Rocky, dusty surface

Question: Which is Earth?

iClicker Question

(a) (b)

iClicker Question

Which is Mars?

(a) (b)

a.  (a) b.  (b)

•  Water has flowed in the past •  But is now locked up as ice in the ground & as polar ice caps •  Drainage features due to short-lived melting events

Water on Mars

•  Blocks of ice floating on a recently frozen sea covered by dust?

•  Dust prevents evaporation

Locked-up Icebergs?

Antarctica

Asteroid Belt

 Between Mars & Jupiter  Millions of rocky bodies  Asteroids tell us composition of solar system •  Some asteroids cross Earth’s orbit

A Bad Day…. 65 Million Years Ago

Chicxulub

• The Impact - Chicxulub Crater (Yucatan) - 300 km underwater crater - billions of tons of sulfur into atm.

• The Asteroid: ~10 km - dinosaur extinction?

1 2

3

Which is which?

iClicker Question

a.  (1) comet; (2) asteroid; (3) meteor b.  (1) meteor; (2) asteroid; (3) comet c.  (1) comet; (2) meteor; (3) comet d.  (1) asteroid; (2) meteor; (3) comet

GG 105 Lecture #20

Jupiter

•  Does Jupiter have a hard surface?

•  90% Hydrogen (H), 10% Helium (He)

•  Jupiter's Great Red Spot - A hurricane the size of 2-3 Earths lasting several centuries

You are looking at the tops of clouds

Action Items for Tuesday, September 1

1.  Register for WileyPLUS 2.  Read Chapter 2 3. Complete homework assignment #2

1. What you should know "2. from today:"

3. 1. Describe the solar nebula hypothesis "4. 2. Understand the Sun and how it works"5. 3. State the ways that Mercury, Venus, and Mars are different from Earth"6. 4. Describe each of the gas giant planets"7. 5. Define a dwarf planet"