Is Our Solar System Unique

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Slide 1

How did the Solar System form?

Is our solar system unique?

Are there other Earth-like planets, or are we a fluke?

Under what conditions can Earth-like planets form?

Is life common or rare?

Slide 2

Ways to Find Out

Look at our own solar system, and think about how it might have formed

Look at other solar systems while they form

Look for and study other solar systems

Create computer models and see if you can produce a solar system

Slide 3

Ways to Find Out

Look at our own solar system, and think about how it might have formed

Look at other solar systems while they form

Look for and study other solar systems

Create computer models and see if you can produce a solar system

Slide 4

Solar System Geometry

Terrestrial planets closer than gas/water giants

Planets get smaller beyond Jupiter

Most planets orbit in the same plane

Some small bodies are tilted

Slide 5

Summary of Planetary Interiors

Slide 6

Slide 7

Summary (Things a formation theory must explain)

The sun, with most of the system mass

Giant planets with solid cores (far from sun)

Terrestrial planets (close to sun)

Most planets orbit in a flat plane

Many planets have moons

Slide 8

Our theory

Solar system formation begins because of gravity - most stuff ends up in the sun

A disk is formed because of rotation

Planet cores form in the disk because

rocks hit and/or gravitationally attract each other

If there’s ice around (> 5 AU from the star, where it’s cold) the cores are bigger. If big enough, they’ll suck gas out of the disk and form giant planets

Moons form via collision or capture or in mini disks

Slide 9

Why might material in clouds collapse to form stars?

What force keeps clouds from collapsing?

Slide 10

Why might material in clouds collapse to form stars?

What force keeps clouds from collapsing?

gas pressure

pushes out

(like in a balloon)

Slide 11