Formation of Our Solar System By the Lunar

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 (counterclockwise viewed from above) Lunar and Planetary Institute image at http: //solarsystem. nasa. gov/multimedia/display. cfm? IM_ID=175

Some more data to explain: 4. Most planets rotate in this same direction Mercury 0° Jupiter 3° Venus 177° Saturn 27° Earth 23° Mars 25° Uranus 98° Neptune 30° NASA images edited by LPI

And some more data to explain: 5. Solar System highly differentiated: Terrestrial Planets (rocky, dense with density ~4 -5 g/cm 3) Jovian Planets (light, gassy, H, He, density 0. 72) Images: Lunar and Planetary Laboratory: http: //solarsystem. nasa. gov/multimedia/display. cfm? IM_ID=178

How Did We Get a Solar System? Image: LPI 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/

How Did We Get a Solar System? Image: LPI Concentrations of dust and gas in the cloud; material starts to collect (gravity > magnetic forces) Hubble image at http: //hubblesite. org/newscenter/archive/releases/nebula/emission/2005/35/image/a/

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? • Rotating, flattening, contracting disk - solar nebula! Equatorial Plane Orbit Direction NASA artwork at http: //en. wikipedia. org/wiki/Image: Ra 4 -protoplanetary-disk. jpg

How Did We Get a Solar System? • After ~10 million years, material in center of nebula hot enough to fuse H • “. . . here comes the sun…” NASA/JPL-Caltech Image at http: //www. nasa. gov/vision/universe/starsgalaxies/spitzer-20060724. html

How Did We Get a Solar System? • Metallic elements (Mg, Si, Fe) condense into solids at high temps. Combined with O to make tiny grains • Lower temp (H, He, CH 4, H 2 O, N 2, ice) - outer edges Planetary Compositions Hubble photo at http: //hubblesite. org/newscenter/archive/releases/star/protoplanetary-disk/2005/10/image/a/layout/thumb/

How Did We Get a Solar System? Inner Planets: • Hot – Silicate minerals, metals, no light elements, ice • Begin to stick together with dust clumps Image: 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 across Image: 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 – 10 x 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

How Did We Get a Solar System? The Asteroid Belt ? Should have been a planet instead of a debris belt? Jupiter kept it from forming Eros image at http: //solarsystem. nasa. gov/multimedia/gallery. cfm? Category=Planets&Object=Asteroids&Page=1

How Did We Get a Solar System? Beyond the Gas Giants - Pluto, Charon and the Kuiper Belt objects Chunks of ice and rock material Little time / debris available to make a planet – slower!!

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 formation) • Lunar samples - 4. 5 to 4. 6 Ga • Meteorites - 4. 56 Ga • Earth – 3. 9 (or 4. 4 Ga) Lunar meteorite at http: //meteorites. wustl. edu/lunar/stones/mac 88105. htm Meteorite photo by Carl Allen at http: //ares. jsc. nasa. gov/Education/Activities/Exp. Met. Mys/. . %5 CSlide. Sets/Exp. Met. Mys/Slides 1 -9. 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 Return 1/15/2006 • Stardust Passed through Comet Wild 2 Coma 1/2004 Stardust image at http: //stardust. jpl. nasa. gov/news 97. 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 at http: //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/ap 000805. html

Comet Parts 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 Nucleus, Coma Dust tail – white, “smoke, ” reflects sun. 600, 000 to 6 million miles long Ion tail – Solar UV breaks down CO gas, making them glow blue. 10’s of millions of miles

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: //www 2. jpl. nasa. gov/sl 9/image 3. html