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Dive into the solar system with "Not Your Parents' Solar System!" as we explore the Sun, planets, asteroids, and comets. Learn through engaging factoids and comparisons, highlighting each celestial body's unique characteristics. Expand your view to the 21st-century perspective by categorizing objects into families and understanding the structure of the solar system. Discover Pluto's intriguing history, its place in the Kuiper Belt, and the ongoing debate about its planetary classification. Engage with expert opinions, including the IAU's stance on Pluto's planetary status. Prepare to expand your cosmic knowledge beyond the traditional solar system understanding.
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Not Your Parents’ Solar System! Frank Summers Space Telescope Science Institute NSTA Institute Symposium November 15, 2003
How I learned the solar system • Sun & 9 planets • Separate section on each • Mention asteroids and comets • Lots of cool facts
Mercury My Venus Very Earth Energetic Mars Mother Jupiter Just Saturn Served Uranus Us Neptune Nine Pluto Pizzas
What’s wrong? • Memorization • Factoids • Highlights differences • Little or no relevance • Little or no “big picture”
An Improvement • Compare and contrast • Discuss broad ideas • Apply to planets, moons, etc., as a group • Highlight similarities • Appearance • Characteristics • Events
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 • 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 • Six families of the solar system • Star • Rocky planets • Asteroid belt • Gas giant planets • Kuiper belt • Oort cloud
500 million miles Thousands of asteroids … about a million miles apart! Scientific View of the Asteroid Belt
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 • Classes of similar objects • Size • Composition • Orbit size • Orbit shape • Orbit inclination • Moons • Rings
Families of the Solar System • Classification • Structure of the solar system • Similar objects lie in similar regions • Clues to solar system formation and evolution
Sun Rocky Planets Asteroid Belt Gas Giant Planets Kuiper Belt Oort Cloud
Sun Mercury Venus Earth Mars Asteroid Belt Jupiter Saturn Uranus Neptune Kuiper Belt Oort Cloud
Some May View Elaborate Mnemonics As Boring, Just Some Useless Nonsensical Knowledge, But Others Cheer
What about Pluto? • Not a rocky planet • Not a gas giant planet • For teachers, it is an opportunity
Planet Pluto • 1930 Tombaugh discovers Pluto
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 • 1995 – Hubble Space Telescope infrared • 1996 – Hubble Space Telescope visible
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 • 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 • 1992 – Jewitt & Luu find object dubbed QB1 • Distance of 42 AU • First (third?) object discovered in the Kuiper Belt
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
Large KBOs • Pluto still larger, but not by that much • Note: plot below doesn’t include Quaoar
Binary KBOs • Pluto/Charon not the only binary object • Nine discovered so far (Nov 2003) • All types of KBOs have binaries
What is Pluto? • You make the call • Singular ice planet • Mutant giant double comet • King of the Kuiper Belt • ???
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 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? • Solar system alone is category of one • What about other solar systems?