The Small Telescope Science Program Deep Impact Mission

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The Small Telescope Science Program Deep
Impact Mission

• Gary Emerson (Ball Aerospace Technologies)
• Stephanie McLaughlin (Univ. of Maryland)
• Lucy McFadden (Univ. of Maryland)

AAVSO Spring 2005 Meeting
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An Overview of Deep Impact

• First experiment to probe beneath the surface of
  a comet to
• Understand the differences between interior and
  surface
• Determine basic cometary properties
• Search for pristine material below surface
• Two-component spacecraft
• Flyby spacecraft and auto-guided, imaging
  impactor
• Launched on January 12, 2005
• Impact with comet 9P/Tempel 1 on July 4, 2005
  will form 100m-wide crater

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Encounter Schematic
ITM-1 E-88 min
Impactor Release E-24 hours
AutoNav Enabled E-2 hr
ITM-2 E-48 min
ITM-3 E-15 min
Tempel 1 Nucleus
2-way S-band Crosslink
500 km
Flyby S/C Deflection Maneuver E-23.5 hr
Science and Autonav Imaging to Impact 800 sec
Shield Mode Attitude through Inner Coma
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Inter-Planetary Trajectory
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9P/Tempel 1

• History
• April 1867 discovered
• 1873, 1879 observed
• 1881 close approach to Jupiter, then lost
• 1967 Recovered
• Jupiter family
• Orbital period 5.5 years
• Perihelion distance 1.5 AU
• Shape 7.2 x 2.2 x 2.2 km
• Albedo 0.04 (very dark!)
• Rotation Period 41.7 hours
• Maximum visual magnitude 9.3

Ernst Wilhelm Leberecht Tempel (1821 - 1889)
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Ground-based Observations

• Science team is conducting a vigorous program of
  ground-based observations
• Volatile outgassing
• Dust coma development
• Jet activity and outbursts
• Goal Establish baselines of Tempel 1s activity
  for comparison to impact and post-impact
  observations
• However, professional observers have limited
  access to large telescopes for mission support...

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Small Telescopes to the Rescue

• Advanced amateurs and private observatories can
  provide good temporal coverage to supplement
  baselines
• Advanced observers typically have
• Fast, wide-field telescopes
• High-quality, commercial CCD cameras
• UBVRI filters
• Combination is good for
• Imaging and aperture photometry of dust coma (RI)
• Wide format captures field stars in same frame as
  comet, simplifying calibrations and photometry
• Imaging and monitoring of jet activity and
  outbursts (VRI)
• Hence, the STSP...

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The Small Telescope Science Program

• The STSP is an E/PO project for the mission
• Proposed by Gary Emerson
• Campaign in 2000 was very successful
• Network of 40 observers in 12 countries,
  spanning 6 continents
• Observers acquired 700 VRI and 300 unfiltered,
  raw CCD images
• Program was in hibernation for past 3 years,
  except for
• Borrelly, Wild 2, LINEAR C/2000 W1
• Relaunched in October 2004
• Continues through 2005

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STSP Filling the Gaps
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Jet Activity and Outbursts?

• Evidence for jet activity 1983 apparition
• Upper 3 months pre-perihelion
• Lower 1 month pre-perihelion
• Expect jet activity 3-4 months before perihelion
  Mar - Jul 2005
• Outbursts? Need continuous imaging
• Expect new active area after impact ? Jets or
  outbursts days or weeks after impact?
• STSP observers Monitor for pre- and post-impact
  activity

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What Were Looking for...

• Advanced amateur observers with discretionary
  telescope time
• Fast, wide-field telescope systems CCDs VRI
  filters
• Aperture photometry (RI) Now through Dec 2005
• VRI imaging for jet activity, outbursts Now
  through Sep 2005
• Narrowband images and spectroscopy also accepted
• Interested? Please contact us!
• Stef McLaughlin (stefmcl_at_astro.umd.edu)
• Gary Emerson (gemerson_at_ball.com)
• Or visit the STSP website
• http//deepimpact.umd.edu/stsp
• Reference The NASA Deep Impact Missions Small
  Telescope Science Program in the Future of Small
  Telescopes in the New Millenium, Astro. Sp.
  Sci. Library, Ed. Terry Oswalt, Vol. 289, Kluwer
  Academic Publishers, 2003, p. 57.

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Tempel 1 is in Virgo