Solar System

Solar System : 

Solar System

How I learned the solar system : 

How I learned the solar system Sun & 9 planets Separate section on each Mention asteroids and comets Lots of cool facts

What’s wrong? : 

What’s wrong? Memorization Factoids Highlights differences Little or no relevance Little or no “big picture”

An Improvement : 

An Improvement Compare and contrast Discuss broad ideas Apply to planets, moons, etc., as a group Highlight similarities Appearance Characteristics Events

Other comparisons : 

Other comparisons Craters – Earth, Moon, Mercury, etc Volcanoes – Mount St. Helens, Olympus Mons, Io, etc Canyons – Grand Canyon, Mariner Valley Storms, Winds, Seasons, Weather, Ice Floes, Magnetic Fields, Moons, Rings, etc

Compare and Contrast : 

Compare and Contrast Messages What happens on Earth happens elsewhere Solar system is understandable Problems Need to establish facts before comparison Big picture still lacking

21st Century View : 

21st Century View Six families of the solar system Star Rocky planets Asteroid belt Gas giant planets Kuiper belt Oort cloud

Slide 16: 

Hollywood’s View of the Asteroid Belt

Slide 17: 

Scientific View of the Asteroid Belt Thousands of asteroids … about a million miles apart!

Slide 20: 

Kuiper Belt

Slide 21: 

Oort Cloud ? Billions of icy minor planets – comet nuclei Roughly spherical out to 50,000 AU Predicted by Jan Oort Explains long-period comets No observations

Families of the Solar System : 

Families of the Solar System Classes of similar objects Size Composition Orbit size Orbit shape Orbit inclination Moons Rings

Families of the Solar System : 

Families of the Solar System Classification Structure of the solar system Similar objects lie in similar regions Clues to solar system formation and evolution

Slide 25: 

Sun Rocky Planets Asteroid Belt Gas Giant Planets Kuiper Belt Oort Cloud

Slide 26: 

Sun Oort Cloud Mercury Venus Earth Mars Asteroid Belt Jupiter Saturn Uranus Neptune Kuiper Belt

Slide 27: 

Some Others Cheer May View Elaborate Mnemonics As Boring, Just Some Useless Nonsensical Knowledge, But

What about Pluto? : 

What about Pluto? Not a rocky planet Not a gas giant planet For teachers, it is an opportunity

Planet Pluto : 

Planet Pluto 1930 Tombaugh discovers Pluto

Double Take: Charon : 

Double Take: Charon 1978 – James Christy (USNO) observations to refine Pluto’s orbit Notices elongated images, deduces moon 1985 – Charon occults Pluto, confirms existence Refined sizes and masses – tiny

First Pictures of Pluto/Charon : 

First Pictures of Pluto/Charon 1995 – Hubble Space Telescope infrared 1996 – Hubble Space Telescope visible

First Pictures of Pluto : 

First Pictures of Pluto

Black Sheep of the Planets : 

Black Sheep of the Planets Pluto is the oddball Size Companion Composition Orbit 3:2 resonance with Neptune Pluto/Charon as double ice planet?

Kuiper Belt : 

Kuiper Belt History 1930 – Leonard mentions possibility of trans-Plutonian objects 1943 – Kenneth Edgeworth postulates objects beyond Pluto 1951 – Gerard Kuiper predicts that a massive Pluto would disperse small objects into a belt 1980 – Fernandez predicts belt that resembles what was eventually found

KBOs : 

KBOs 1992 – Jewitt & Luu find object dubbed QB1 Distance of 42 AU First (third?) object discovered in the Kuiper Belt

More and more KBOs : 

More and more KBOs Large searches for KBOs ensued Hundreds discovered within a decade Over 600 so far (Nov 2003) Over 70,000 predicted with diameters > 100 km, orbits 30-50 AU Plutinos – Neptune resonance Scattered – Neptune affects orbit Classsical – Separated from Neptune

Slide 41: 

Pluto/Charon orbits within Kuiper Belt

Large KBOs : 

Large KBOs Pluto still larger, but not by that much Note: plot below doesn’t include Quaoar

Binary KBOs : 

Binary KBOs Pluto/Charon not the only binary object Nine discovered so far (Nov 2003) All types of KBOs have binaries

What is Pluto? : 

What is Pluto? You make the call Singular ice planet Mutant giant double comet King of the Kuiper Belt ???

Kuiper Belt Expert’s View : 

Kuiper Belt Expert’s View “So, bluntly put, one has two choices. One can either regard Pluto as the smallest, most peculiar planet moving on the most eccentric and most inclined orbit of any of the planets or one can accept that Pluto is the largest known, but otherwise completely typical, Kuiper Belt Object. The choice you make is up to you, but from the point of view of trying to understand the origin and significance of Pluto it clearly makes sense to take the second option.” Dave Jewitt, University of Hawaii

IAU Official Position : 

IAU Official Position IAU defines Pluto to be a planet IAU cannot define “planet” Upper limit: not massive enough to produce any form of fusion at its core Deuterium fusion occurs for objects about 15 times Jupiter’s mass No lower limit specified Reasonable lower limit? Massive enough for gravity to make it spherical At least 13 planets No reasonable definition produces 9 planets

What is a Planet? : 

What is a Planet? Solar system alone is category of one What about other solar systems?

Slide 52: 

Beta Pictoris

Disks around Other Stars : 

Disks around Other Stars Lots of them Proplyds – proto-planetary disks Kuiper Belt sized and larger Some substructure seen

Planets around Other Stars : 

Planets around Other Stars Cannot see directly (yet) Detect via gravitational pull on star Wobble Periodic shift of spectral lines Monitor for many years (several orbits) Large gas giant planets detectable

Planets around Other Stars : 

Planets around Other Stars Current count (Nov 2003) 102 planetary systems 117 planets 13 multiple planet systems At least 15% of sun-like stars have planets

Planets around Other Stars : 

Planets around Other Stars Jupiter mass planets in Mercury orbits Elliptical orbits Multiple Jupiter sized planets Saturn mass planets detected (2003) Planets around pulsars

Perspective on the Solar System : 

Perspective on the Solar System Our solar system is the oddball Need to generalize our formation and evolution scenarios Implications for life in the universe Lots of planets Stability of orbits? New era of solar system study