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1. Solar System Differentiation2. Planetary Differentiation3. Radiometric Dating4. Solar System Motions
Solar System Differentiation
Solar System Differentiation
All of the heavy elements are born in a supernova.
Solar System Differentiation
Solar System Differentiation
Inner Solar System is HOT• Light elements (H, He) and “ices” vaporized• Blown out of the inner Solar System by solar wind• Only heavy elements (Fe, Ni) are left
Outer Solar System is COLD• Too cold to evaporate ices to space• Rock and ice “seeds” grew large enough to attract
gasses (H, He)
Planetary Differentiation
Planetary Differentiation
Planetary Differentiation
As the planets cooled the layers settled out according to density.
Planetary Differentiation
Chondrites, a type of meteorite, do not show this differentiation.
• Meteoriteshttp://www.markelowitz.com/meteorites.html
Planetary Differentiation
The gravitational force of the inner planets is too weak to hold on the lighter elements like H and He. (THINK about a Helium balloon.)
Radiometric Dating
Abbreviations:P = Protons N = Neutrons e- = Electrons
Radiometric Dating
Absolute Age – the numeric age of an object or event
Radiometric Dating – a method of determining the absolute age of an object by comparing the relative percentages of a radioactive (parent) isotope and a stable (daughter) isotope
Radiometric Dating
Inside the nucleus of an atom are P and N
The # of P in the nucleus determines what the element is (for example Carbon always has 6 P)
Label the atom
Radiometric Dating
The # of N can vary.
Atoms of the same element that have different # of N are called isotopes.
Radiometric Dating
P = Protons N = Neutrons e- = Electrons
If you change the # of P you change the atom itself.
If you change the # of N you create an isotope.
If you change the # of e- you create an ion (charged atom).
Radiometric Dating
All elements with atomic numbers greater than 83 are radioisotopes meaning that these elements have unstable nuclei and are radioactive.
Radiometric Dating
Radioactive Decay The unstable (radioactive) isotopes decays to form a new (daughter) isotope.
Decays at a constantrate.
https://www.youtube.com/watch?v=cKJMk2Oiod0
Radiometric Dating
Types of Radioactive Decay
Alpha DecayBeta DecayGamma Rays
https://www.youtube.com/watch?v=5oUagoF_viQ
Radiometric Dating
Half Life
The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter Isotope.
Compare relative percentages of the parent and daughter isotopes to get the age.
Radiometric Dating
Radioactive Isotopes
Used to determine the age of the earth
• Uranium-238, or 238U • Daughter, lead-206 • Half-life 4.5 billion years
• Potassium-40, or 40K, • Argon-40 • Half-life of 1.25 billion years
Radiometric Dating
Zircons
Zircons are volcanic crystals that contain the radioactive element uranium, which are called “ geologic clocks” because uranium converts to the element lead at a specific rate over a long span of time.
Planetary Motions
Kepler’s came up with three laws of planetary motion based on Tycho Brahe’s observations of the night sky.
Planetary Motions
Kepler’s 1st Law - The Law of the Ellipses • The orbit of a planet is an ellipse with the sun at one
focus.
A path connecting the two foci to the ellipse always has the same length.
Planetary Motions
Kepler’s 2nd Law - The Law of Equal Areas• The line joining a planet and the sun sweeps equal
areas in equal time.
The planet moves slowly here.
The planet moves quickly here.
Dt
Dt
Planetary Motions
Kepler’s 3rd Law - The Law of Periods• Compares the orbital period and radius of an
orbit of a planet to those of other planets.
http://astro.unl.edu/naap/pos/animations/kepler.swf
Kepler Space Telescope
Confirmed Planets = 136Unconfirmed Planets = 3,548
Planets within the habitable zone = 272
Kepler Space Telescope Reporting:
http://youtu.be/EmsYCbYu-LA
50 years of exploration
Published by National Geographic
Voyager 1Beginning with
http://goldenrecord.org/http://voyager.jpl.nasa.gov/multimedia/JPLvoyagerModule/JPLvoyagerModule.html
Back to the Facts
http://youtu.be/uhcKaFQD7l0
Venus spins the wrong way ??????
Uranus rains diamonds ??????
Venus
New theory: suggests that Venus may not have flipped at all… instead its rotation slowed to a standstill and then reversed direction. Taking into account other factors … tidal effects from other planets, etc … Venus's axis could have shifted due to a variety of positions throughout the planet's evolution.
Uranus
Uranus contains methane … which can turn into diamond at high temperatures and pressures.
Allowing diamonds to fall like raindrops or hailstones …
• http://www.indiana.edu/~geol105/images/gaia_chapter_3/earth_differentiation.htm• http://geology.indiana.edu/h205_2/index.html• http://www.psrd.hawaii.edu/Sept05/PortalesValley.html• https://www.agi.com/resources/educational-alliance-program/astro-primer/primer1.htm
• Movie:https://www.youtube.com/watch?v=Q_3PFfMdZ9c
Want to learn more:http://wisp.physics.wisc.edu/astro104/lecture28/lec28_print.html
Planet Poetry:http://spaceplace.nasa.gov/review/story-superstar/text-version.html