Not Your Parents Solar System! Dr. Frank Summers Space Telescope Science Institute July 11, 2013
Your Ancient Ancestors Solar System
Earth Moon Mercury Venus Sun Mars Jupiter Saturn
Claudius Ptolemy 150 Almagest
Misconception Ptolemy invented the Earth-centered solar system.
Misconception Ptolemy invented the Earth-centered solar system. Ptolemy organized and systematized the Earth-centered solar system based on ideas that had been developed over about 600 years.
Your Parents Solar System
Nicholas Copernicus 1543 On the Revolutions of Heavenly Spheres
Misconception Copernicus delayed publishing because he feared criticism from religious leaders.
Misconception Copernicus delayed publishing because he feared criticism from religious leaders. Copernicus delayed publishing (in part) because he feared criticism from scientists.
Earth Moon Mercury Venus Sun Mars Jupiter Saturn
Sun Mercury Venus Earth / Moon Mars Jupiter Saturn
Misconception Copernicus Sun-centered solar system was quickly accepted because it was much simpler and more accurate.
Misconception Copernicus Sun-centered solar system was quickly accepted because it was much simpler and more accurate. Copernicus Sun-centered solar system was just as complex as Ptolemy s Earth-centered solar system, and provided no more accuracy in its predictions.
Galileo 1609 Use of telescope for astronomy 1632 Trial by the Inquisiton
Misconception Galileo invented the telescope and was the first to use it for astronomy.
Misconception Galileo invented the telescope and was the first to use it for astronomy. Galileo was one of several folks who improved the spyglass so that it could be used for astronomy.
Misconception Galileo proved that Copernicus Suncentered solar system was correct.
Misconception Galileo proved that Copernicus Suncentered solar system was correct. Galileo tried to prove Copernicus Suncentered solar system, but his arguments were wrong.
Tycho Brahe 1546-1601 Johannes Kepler 1571-1630
Misconception Astronomers embraced the Suncentered solar system because it is philosophically simpler.
Misconception Astronomers embraced the Suncentered solar system because it is philosophically simpler. Astronomers embraced the Suncentered solar system only when it could provide better predictions.
Isaac Newton 1687 Principia
William Herschel 1781 Discovery of Uranus
1801 Planet Ceres (Piazzi)
1801 Planet Ceres (Piazzi) 1802 Planet Pallas (Olbers) 1804 Planet Juno (Harding) 1807 Planet Vesta (Olbers) 1845 Planet Astraea (Hencke)
Urbain Le Verrier & John Couch Adams 1846 Prediction and discovery of Neptune
Rocky Planets Giant Planets
Misconception You can t just demote a planet!
Misconception You can t just demote a planet! In the mid-1800 s, astronomers demoted the many planets between Mars and Jupiter to be asteroids.
Clyde Tombaugh 1930 Discovery of Pluto
Misconception Pluto s discovery relied on mathematical predictions based on perturbations in Neptune s orbit.
Misconception Pluto s discovery relied on mathematical predictions based on perturbations in Neptune s orbit. Pluto s discovery relied solely on the incredible observing skill and dedication of Clyde Tombaugh. Neptune s orbit shows none of the claimed perturbations.
Your Parents Solar System
Your Parents Solar System
Your Parents Solar System
Mercury My Venus Very Earth Energetic Mars Mother Jupiter Just Saturn Served Uranus Us Neptune Nine Pluto Pizzas
Facts Are Not Knowledge Memorization, not understanding Factoids Highlights differences Little or no relevance Little or no big picture
Comparative Planetology
An Improvement Compare and contrast Discuss broad ideas Apply to planets, moons, etc., as a group Highlight similarities Appearance Characteristics Events
April 1997 September 1997
Planetary Comparisons Canyons Grand Canyon, Mariner Valley Volcanoes Mount St. Helens, Olympus Mons, Io Craters Earth, Moon, Mercury, Storms, Winds, Seasons, Weather, Ice Floes, Magnetic Fields, Moons, Rings, etc
Comparative Planetology Messages What happens on Earth happens elsewhere Solar system is understandable Pieces to assemble the big picture
The 21 st Century Solar System Sun Rocky Planets Asteroid Belt Giant Planets Kuiper Belt Oort Cloud
Families of the Solar System Classes of similar objects Size Composition Orbit size Orbit shape Orbit inclination Moons Rings
Hollywood s View of the Asteroid Belt
Hundreds of thousands of asteroids about a million miles apart! 960 million miles Scientific View of the Asteroid Belt
Sizes of the Giant Planets and Earth
Kuiper 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
Figure 1a: Comet Semimajor Axis Distribution 600 Orbital Period: 200 years 7 years 500 Number of Comets 400 300 200 100 0-0.004-0.002 0.000 0.002 0.004 0.009 0.020 0.042 0.088 0.185 0.390 Long Period Short Period 1 / a (1/AU)
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 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
Science May View Established Models As Basic Justified Standards Until New Knowledge Bears Out Changes
Sometimes My Very Energetic Mother Also Boils Jumbo Shrimp Using Nine Kettles Bubbling Over Coals
The Inevitable Question
Why is Pluto No Longer a Planet?
Planet Pluto January 23, 1930 January 29, 1930
Pluto/Charon 1978 James Christy (USNO)
The Incredible Shrinking Planet Lowell s Planet X 7 times Earth 1940 s 1 times Earth 1980 0.1 times Earth 1985 0.002 times Earth
Kuiper Belt Objects 1992 Jewitt & Luu find QB1 Distance of 42 AU First (third?) object discovered in the Kuiper Belt
Kuiper Belt
But Isn t Pluto Special in Some Way?
Orbit Comparison: Pluto/Charon vs 2004 DW
Kuiper Belt
Moon
Makemake Haumea, Hi iaka & Namaka Eris & Dysnomia
KBO Size Comparison
Pluto vs the Kuiper Belt Orbit similar to KBOs Size similar to KBOs KBO companions common Composition similar to KBOs
Pluto vs the Kuiper Belt Orbit similar to KBOs Size similar to KBOs KBO companions common Composition similar to KBOs Pluto has found its family!!
IAU Definition August 2006 IAU defines planet 1. Orbits the Sun 2. Upper mass limit not massive enough to produce fusion Deuterium fusion occurs at about 15x Jupiter s mass 3. Lower mass limit Massive enough for gravity to make it spherical About 500 miles in diameter 4. Dominates its orbit Dwarf planets meet 1, 2, 3, but not 4
Other Planetary Systems? Solar system alone is category of one
HR 8799
Planets around Other Stars Jupiter mass planets in Mercury orbits Elliptical orbits Multiple Jupiter sized planets Planets around pulsars
Planetary System Formation Planetary systems form in a predictable fashion from a spinning circular disk
Sun Rocky Planets Asteroid Belt Giant Planets Kuiper Belt Oort Cloud
So Much to Discover 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
Presentation Materials http://tinyurl.com/pa-gsfc-2013 Online Sessions Google Hangout September Info to come Social media Facebook.com/DrFrankSummers Twitter @drfranksummers