Transcript differentiation, dating, and motions

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Solar System Differentiation
Planetary Differentiation
Radiometric Dating
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.
• Meteorites
http://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)
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 constant
rate.
https://www.youtube.com/watch?v=cKJMk2Oiod0
Radiometric Dating
Types of Radioactive Decay
Alpha Decay
Beta Decay
Gamma 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.
Dt
The planet moves
slowly here.
Dt
The planet moves
quickly here.
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/animation
s/kepler.swf
Kepler Space Telescope
http://youtu.be/EmsYCbYu-LA
Kepler Space Telescope Reporting:
Confirmed Planets = 136
Unconfirmed Planets = 3,548
Planets within the habitable zone = 272
50 years of exploration
Published by National Geographic
Beginning with
http://goldenrecord.org/
http://voyager.jpl.nasa.gov/multimedia/JPLvoyagerModule/JPLvoyagerModule.html
Voyager 1
Back to the Facts
Venus spins the wrong way ??????
Uranus rains diamonds ??????
http://youtu.be/uhcKaFQD7l0
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 …
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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