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