Ch 4 Solar System part 2

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Ch 4 - Solar System part 2
Asteroid Eros
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Presentation on Radio Astronomy

• A visitor will be talking about radio astronomy
  in the FYE section of Physics 101 on Friday at 2
  p.m. here in room Currens 205. The level will be
  appropriate for this course.
• Dr. Esteban D. Araya of the Univ. of New Mexico
  will talk for about 40 minutes.
• You will get 2 added to your final course score
  for attending (there will be a paper to sign).
  All Physics 101 students are welcome to attend.
• Then, at 4 p.m. he will give a more advanced talk
  (no extra credit, but all are welcome).

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Exam 2

• Next Tuesday, March 3
• Covers Ch. 2, 3, and 4

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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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The Solar System
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The Solar System
There are several kinds of objects in our Solar
System Terrestrial planets Jovian
planets debris asteroids, comets and
meteoroids and some objects still being
classified Kuiper Belt, Oort cloud
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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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Asteroids three major groupsAsteroid belt
between the orbits of Mars and JupiterTrojan
AsteroidsNear-Earth Objects
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The Inner Solar System (sizes NOT to scale)
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Asteroids and meteoroidsare small rocky
objectsThe main difference between the two is
size.
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Asteroid Eros was imaged by a spacecraft which
then landed on it and sent back data on its
composition.NEAR spacecraft site
http//near.jhuapl.edu/For a simulation of the
trajectory see http//ssd.jpl.nasa.gov/sbdb.cgi?
sstr433orb1
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The Asteroid belt contains over 100,000
asteroids, (fact sheet) Ceres (sîr'ez link
dictionary.com) (called a dwarf planet in 2006)
and Vesta (ves'-t?) (a minor body link or
asteroid) are currently targeted for detailed
study http//antwrp.gsfc.nasa.gov/apod/ap070622.h
tml Ceres is in opposition right now! (magnitude
6.9) http//www.skyandtelescope.com/observing/obj
ects/asteroids/35387769.html A spacecraft named
DAWN was launched in Sept. 2007 and will arrive
in 2011 to begin studying these two objects
http//antwrp.gsfc.nasa.gov/apod/ap070929.htmlhtt
p//www.nasa.gov/missions/current/index.html
http//www.nasa.gov/mission_pages/dawn/main/index
.html More on asteroids http//www.solstation
.com/stars/asteroid.htmhttp//planetary.org/explo
re/topics/asteroids_and_comets/ceres.html
http//planetary.org/explore/topics/asteroids_and
_comets/vesta.html
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Barringer Crater in Arizona a meteor crater
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Manicouagan Reservoir a crater in Canada
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Near Earth Objects - NEO
There is an automated system to scan the sky for
near-Earth objects and report them to a computer
system. http//www.ll.mit.edu/LINEAR/ These
and other reports are fed into a computer program
called the JPL Sentry system http//neo.jpl.nasa
.gov/risk/ This detected a threat last year, at
risk level 2 http//neo.jpl.nasa.gov/news/news14
9.html which is no longer considered a threat.
For further descriptions http//neo.jpl.nasa.g
ov/ Asteroid 1950 DA may collide with Earth in
the year 2880 (1 in 300 chance)
http//neo.jpl.nasa.gov/1950da/
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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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Comets

• Icy snowball model
• Two tails may appear ion tail and dust tail
• Comet Hale-Bopp (1997) http//antwrp.gsfc.nasa.gov
  /apod/ap050522.html
• Tails are influenced by the environment as well.
• Recent news comet tail blown off by solar wind
  (called a Coronal Mass Ejection CME) and seen by
  a spacecraft. Comet Encke was near the Sun when
  this happened April 20, 2007. (next slide)

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Comet Encke ion (or plasma) tail blown
completely off by a Coronal Mass Ejectionsee
APOD 10/3/07 for details link
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Halleys Comet close-up by a passing spacecraft
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Probes of asteroids and comets
The NASA Deep Impact mission was sent to collide
with a comet on July 4, 2005 http//www.nasa.g
ov/mission_pages/deepimpact/main/index.html
Rosetta mission http//rosetta.esa.int/scien
ce-e/www/area/index.cfm?fareaid13
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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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A Comet Trajectory is usually a very narrow
ellipse, with eccentricity near 1.0Some
comets appear to come from almost 100,000 A.U.
from the Sun, in a region called the Oort
cloud.
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Comet Reservoirs the Oort Cloud the
Kuiper Belt (pronounced Kye-per)
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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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Meteor Trails in the night sky
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Meteor Showers are probably due to old comets.
There is definite proof that some are due to
known comets. Others are probably fragments of
asteroids.
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Meteorite Samples, stony vs. iron-nickel
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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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• Major facts that any theory of solar-system
  formation must explain
• Each planet is relatively isolated in space.
• The orbits of the planets are nearly circular.
• The orbits of the planets all lie in nearly the
  same plane.
• Direction of planets movement in orbit is same
  as suns rotation.
• Direction of planets rotation is same as suns
  rotation. (usually)
• Direction of the various moons revolution is
  same as planets rotation.
• The planetary system is highly differentiated.
• Asteroids are very old, and not similar to
  terrestrial planets or Jovian planets.
• The Kuiper belt is a group of asteroid-sized icy
  bodies orbiting outside the orbit of Neptune.
  (KBO Kuiper Belt Objects)
• The Oort Cloud is composed of icy cometary
  objects that do not orbit in the same plane as
  the planets (the ecliptic).

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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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Angular Momentum influences the formation of
planetary disks in the collapse of a cloud of gas
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Beta Pictoris is one example of a
protoplanetary disk
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Conservation of Angular Momentum
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Conservation of Angular Momentum in a figure
skater. (demo)
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A Dark Cloud is actually gas dense enough to
block starlight.
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A Theory of Solar System Formation a
spinning gas cloud condenses to a much smaller
size, and begins to rotate much faster due to
conservation of angular momentum. This process
explains the fact that all the objects tend to
rotate (CCW) in the same way (or sense).
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Jovian Condensation due to whirlpools?
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Differentiation may be due to the temperatures in
the Early Solar NebulaThe inner solar system
is closer to the early Sun, and so it is hotter.
Volatile gases are not condensed on the planets
and end up condensing in the Jovian planets
further out. This is similar to a process in
chemical plants called distillation or
fractionation.
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Planetesimal Ejection might account for the Oort
cloud. This also eliminated large impacts on
Earth after an initial period, and allowed life
to evolve.
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• LEARNING GOALS Studying this chapter
  will enable you to
• Describe the scale and structure of the solar
  system and list the basic differences between the
  terrestrial and the jovian planets.
• Summarize the orbital and physical properties of
  the major groups of asteroids.
• Describe the composition and structure of a
  typical comet and explain how cometary tails
  form.
• Explain what cometary orbits tell us about the
  probable origin of comets.
• Summarize the orbital and physical properties of
  meteoroids and explain how these bodies are
  related to asteroids and comets.
• List the major facts that any theory of
  solar-system formation must explain and indicate
  how the leading theory accounts for them.
• Outline the process by which planets form as
  natural by-products of star formation.
• Outline the properties of the known extrasolar
  planets, and discuss how they fit in with current
  theories of solar-system formation.

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Extra-solar Planets are revealed by Doppler
effectsee spectral analysis ppt
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Extrasolar Orbits most are very large planets
close to the star, so probably much too hot to
support life.
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Sinking Planet theory of giant planets close to a
star.
Who keeps count? For more about extrasolar
planets, see these web sites http//exoplanets
.org/ 228 http//exoplanet.eu/ 342
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More on exoplanets
For more about extrasolar planets, see these web
sites http//exoplanets.org/
228 http//exoplanet.eu/ 342 http//en.wikipedia
.org/wiki/List_of_stars_with_confirmed_extrasolar_
planets NASA is launching a satellite on March
5 to look for exoplanets http//planetquest.jpl.
nasa.gov/Kepler/kepler_index.cfm
http//www.nasa.gov/mission_pages/kepler/main/ind
ex.html First direct image of an exoplanet (in
infrared) http//antwrp.gsfc.nasa.gov/apod/ap050
510.html Fomalhaut has a planet, imaged in
visible light http//antwrp.gsfc.nasa.gov/apod/a
p081114.html Multi-planet star system (Keck
infrared image) http//antwrp.gsfc.nasa.gov/apod
/ap081117.html