formation of our solar system by the lunar and planetary institute for use in teacher workshops...
TRANSCRIPT
Formation of Our Solar System
By the Lunar and Planetary Institute
For Use in Teacher Workshops
Image: Lunar and Planetary Laboratory: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=178
Some data to explain:1. Planets isolated
2. Orbits ~circular / in ~same plane
3. Planets (and moons) travel along orbits in same direction…. same direction as Sun rotates (counter-clockwise viewed from above)
Lunar and Planetary Institute image athttp://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=175
Some more data to explain:
4. Most planets rotate in this same direction
NASA images edited by LPI
Mercury 0° Venus 177° Earth 23° Mars 25°
Jupiter 3° Saturn 27° Uranus 98° Neptune 30°
And some more data to explain:
5. Solar System highly differentiated:
Terrestrial Planets (rocky, dense with density ~4-5 g/cm3)
Jovian Planets (light, gassy, H, He, density 0.7-2)
Images: Lunar and Planetary Laboratory: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=178
How Did We Get a Solar System?
Huge cloud of cold, thinly dispersed interstellar gas and dust – threaded with magnetic fields that resist collapse
Hubble image at http://hubblesite.org/newscenter/archive/releases/nebula/emission/2006/41/image/a/
Image: LPI
Concentrations of dust and gas in the cloud; material starts to collect (gravity > magnetic forces)
How Did We Get a Solar System?
Hubble image at http://hubblesite.org/newscenter/archive/releases/nebula/emission/2005/35/image/a/
Image: LPI
How Did We Get a Solar System?
Gravity concentrates most stuff near center
Heat and pressure increase
Collapses – central proto-sun rotates faster (probably got initial rotation from the cloud) Image: LPI http://www.lpi.usra.edu/education/timeline/gallery/slide_1.html
How Did We Get a Solar System?
NASA artwork at http://en.wikipedia.org/wiki/Image:Ra4-protoplanetary-disk.jpg
•Rotating, flattening, contracting disk - solar nebula!
Equatorial Plane
Orbit Direction
•After ~10 million years, material in center of nebula hot enough to fuse H
•“...here comes the sun…”
How Did We Get a Solar System?
NASA/JPL-Caltech Image at http://www.nasa.gov/vision/universe/starsgalaxies/spitzer-20060724.html
How Did We Get a Solar System?
Hubble photo at http://hubblesite.org/newscenter/archive/releases/star/protoplanetary-disk/2005/10/image/a/layout/thumb/
•Metallic elements (Mg, Si, Fe) condense into solids at high temps. Combined with O to make tiny grains
•Lower temp (H, He, CH4, H2O, N2, ice) - outer edges
Planetary Compositions
How Did We Get a Solar System?
Inner Planets:•Hot – Silicate minerals, metals, no light elements, ice
•Begin to stick together with dust clumpsImage: LPI http://www.lpi.usra.edu/education/timeline/gallery/slide_3.html
How Did We Get a Solar System?
•Accretion - particles collide and stick together … or break apart … gravity not involved if small pieces
•Form planetesimals, up to a few km acrossImage: LPI http://www.lpi.usra.edu/education/timeline/gallery/slide_3.html
How Did We Get a Solar System?
•Gravitational accretion: planetesimals attract stuff
•Large protoplanets dominate, grow rapidly, clean up area ( takes ~10 to 25 My)Image: LPI http://www.lpi.usra.edu/education/timeline/gallery/slide_4.html
How Did We Get a Solar System?
Outer Solar System
•Cold – ices, gases – 10x more particles than inner
•May have formed icy center, then captured lighter gases (Jupiter and Saturn first? Took H and He?)
Image: LPI http://www.lpi.usra.edu/education/timeline/gallery/slide_5.html
The Asteroid Belt? Should have been a planet instead of a
debris belt? Jupiter kept it from forming
How Did We Get a Solar System?
Eros image athttp://solarsystem.nasa.gov/multimedia/gallery.cfm?Category=Planets&Object=Asteroids&Page=1
Beyond the Gas Giants - Pluto, Charon and the Kuiper Belt objects
Chunks of ice and rock materialLittle time / debris available to make a planet
– slower!!
How Did We Get a Solar System?
Play Doh Activity
Early in the Life of Planets
• Planetesimals swept up debris• Accretion + Impacts = HEAT• Eventually begin to melt materials• Iron, silica melt at different
temperatures• Iron sank – density layering
Image from LPI: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=168
Pause to recall the Play Doh accretion activity
But wait, there’s more …. We can differentiate!
When did Our Solar System Form … How do We Know?
Image: Lunar and Planetary Laboratory: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=178
When Did the Solar System Form?
• 4.56 billion years ago
• How do we know? (evidence for formation)
Meteorite photo by Carl Allen athttp://ares.jsc.nasa.gov/Education/Activities/ExpMetMys/..%5C..%5CSlideSets/ExpMetMys/Slides1-9.htm
•Lunar samples - 4.5 to 4.6 Ga•Meteorites - 4.56 Ga•Earth – 3.9 (or 4.4 Ga)
Lunar meteorite athttp://meteorites.wustl.edu/lunar/stones/mac88105.htm
How Do We Know How Our Solar System Formed?
Solar System Samples
Meteorites
Image: http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=2093 And http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-asteroids.html
• Earliest history of Solar System - chemical and physical info about formation and building blocks of planets (rest of stuff was pulled into the Sun or other planets….)
Sample Return1/15/2006
• StardustPassed through Comet Wild 2 Coma 1/2004
Stardust image athttp://stardust.jpl.nasa.gov/news/news97.html
Info and images at http://deepimpact.jpl.nasa.gov/index.cfm
We Can Also Look Around ….
Close-up of "Proplyds" in Orion
Thanks Hubble!
Hubble images athttp://hubblesite.org/newscenter/archive/releases/nebula/emission/1994/24/image/a/ and
http://hubblesite.org/newscenter/archive/releases/nebula/emission/1994/24/image/b/
Comets
• Dirty snowballs - small objects of ice, gas, dust, tiny traces of organic material
Image from: http://antwrp.gsfc.nasa.gov/apod/ap000805.html
Comet Parts
Nucleus, ComaDust tail – white, “smoke,” reflects sun. 600,000 to 6 million miles longIon tail – Solar UV breaks down CO gas, making them glow blue. 10’s of millions of miles
Image from http://hubblesite.org/newscenter/archive/releases/2004/52/image/a/
Image credit: K. Jobse, P. Jenniskens and NASA Ames Research Center http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=903
Naming Comets
NASA/ JPL image of Comet Halley at http://www.solarviews.com/cap/comet/haldet.htm
Where do Comets Originate?
What’s in a Tail?
Image credit: K. Jobse, P. Jenniskens and NASA Ames Research Center http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=903
Comet – Planet Interactions
Image from http://www2.jpl.nasa.gov/sl9/image3.html