Primitive Icy Worlds

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Primitive Icy Worlds
The distant outer edge of our solar system
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How do planetary systems form?

• Protoplanetary discs are seen around dozens of
  young stars.
• Our understanding of solar system formation
• Dust cloud
• Begins to coalesce due to gravity
• It spins conserving angular momentum
• A flattened protoplanetary disc is formed
• Planets condense within the disc sweeping up
  material
• Outer diffuse region doesnt condense, leaving
  primitive icy bodies

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Solar System Formation
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Primitive Icy Bodies

• 3 Regions of the Solar System

• Inner Terrestrial Planets - small, rocky,
  hydrogen (hence H2O CH4) poor
• Giant Planets - mostly H He, most of solar
  system mass other than sun
• Ice Dwarf - leftovers from solar system
  formation - volatile primordial material -
  water, organics, the stuff of life
• KBOs deflected inward as comets bring volatiles
  to terrestrial planets
• KB depleted by comets 10 1000 times more
  mass in the first billion yrs.

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Known KBOs (and Centaurs) today
Red Lowell Obs Survey Open other Centaurs
5 to 30 AU Dotted Blue 50 AU
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Comet missions and KBO mission
KBOs - the least processed material we can access
now. KB formed closer to sun and was kicked
outward by giant planets. Minimally processed
by sun. Comets - are easier we can wait for
nature to deliver KBOs to us, but in the
delivery they come close to the sun. Conclusion
it is scientifically important to study both
KBOs and Comets.
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Missions to Primitive Icy Bodies
Kuiper Belt Objects
New Horizons mission to Pluto, Charon, Kuiper
Belt
Comets
Stardust - returning with samples of comet Wild
2 Deep Impact - on its way to comet Tempel
1 Rosetta (ESA) - on its way to comet
Churyumov- Gerasimenko
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New Horizons Mission to Pluto and the Kuiper Belt

• Denis Bogan, Program Scientist
• Kurt Lindstrom, Program Executive

Yellow Pluto orbit Others- Ju, Sa, Ur, Np Red
NH trajectory
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New Horizons Mission to Pluto and the Kuiper Belt

• Strategic questions addressed by New Horizons
  Mission.
• How do planets form and how have they evolved
  over the lifetime of the solar system?
• How are the planets alike and how do they differ
  and why?
• What physical and chemical conditions and history
  must a planet have in order to be suitable for
  life?
• How were the ingredients for life, water and
  simple organic substances, brought to the inner
  (terrestrial) planets?

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New Horizons Mission to Pluto and the Kuiper Belt

• Understand the three regions of the solar system,
  terrestrial planets, giant planets, and primitive
  icy bodies, and how they relate to each other.
• How much of the terrestrial planets endowments
  of water and organics was delivered by primitive
  icy bodies? How much was here all along?
• What is the history of the Kuiper Belt? How much
  larger was it in the past?
• What is the history of cometary delivery and to
  what extent does it continue today?
• Understand how distance from the suns radiation
  affects the speed of a planets evolutionary
  clock. Can we safely infer (as is generally
  done) that more distant objects hold clues to our
  past?

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New Horizons Mission to Pluto and the Kuiper Belt

• Group 1 (required) Science Objectives
• Characterize the global geology and morphology of
  Pluto and Charon.
• Map surface composition of Pluto and Charon.
• Characterize the neutral atmosphere of Pluto and
  its escape rate.
• Additional Science Objective
• To fly by one or more Kuiper Belt Objects (KBOs)
  after flying by Pluto.
• No identified targets as of Feb. 2006. (Searches
  underway)
• Pluto and Charon are KBOs.

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New Horizons Spacecraft
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New Horizons Instruments
Visible, Infrared, and Ultraviolet spectrometers
Ralph (MVIC and LEISA), Alice) Visible,
infrared, and Ultraviolet imagers (Ralph, Alice,
and LORRI) Solar wind and energetic particle
detectors (SWAP PEPSSI) Radio Science,
communication and navigation (REX) Student
Dust Counter (SDC) - built operated and
interpreted by students will collect data for the
entire trip
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The Student Dust Counter A New Kind of EPO

• EPO Goal Give students a chance to design,
  build, operate, study data from a planetary
  flight experiment.
• Science Goal Make the first dust density
  size spectrum observations beyond 18 AU.
• Students have the primary responsibility for the
  design and development of the SDC over 35 first
  generation students were involved at CU, with
  dozens more participating across the U.S.
• Four Generations of Students To Be Involved.

First generation SDC Student Team Leaders
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New Horizons Science in a Nutshell
NH as a time machine - We will look back 4.5
billion years in time to see what our solar
system was like in the beginning NH as a window
on the universe - We will not only learn much
about our system but also how planetary systems
form in distant galaxies NH as a window on the
first life on Earth - We will study the chemical
building blocks from which life arose