The Formation of Our Solar System

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Crust eventually forms from lightest material

Slide 21

Planetary Interiors

Differentiation

Continues!

Radioactive decay = primary heat source

Partial melting of mantle material  rising magma  volcanoes / lava flows

Slide 22

Pause to recall the Play Doh accretion activity

But wait, there’s more ….

We can differentiate!

Slide 23

When did Our Solar System Form … How do We Know?

Image: Lunar and Planetary Laboratory:

Slide 24

When Did the Solar System Form?

4.56 billion years ago

How do we know? (evidence for formation)

Meteorite photo by Carl Allen at

Lunar samples - 4.5 to 4.6 Ga

Meteorites - 4.56 Ga

Earth – 3.9 (or 4.4 Ga)

Lunar meteorite at

Slide 25

How Do We Know How Our Solar System Formed?

Slide 26

Solar System Samples Meteorites

Slide 27

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

Slide 28

We Can Also Look Around ….

Close-up of "Proplyds" in Orion

Thanks Hubble!

Hubble images at

Slide 29

Comets

Dirty snowballs - small objects of ice, gas, dust, tiny traces of organic material

Slide 30

Comet Parts

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

Slide 31

Naming Comets

NASA/ JPL image of Comet Halley at

Slide 32

Where do Comets Originate?

Slide 33

What’s in a Tail?