AstroCon2004 - Jul 23sam - 1 The Small Telescope Science Program Deep Impact Mission Stephanie...

AstroCon2004 - Jul 23 sam - 1

The Small Telescope Science The Small Telescope Science ProgramProgram

Deep Impact MissionDeep Impact Mission

Stephanie McLaughlin (Univ. of Maryland)Stephanie McLaughlin (Univ. of Maryland)

Lucy McFadden (Univ. of Maryland)Lucy McFadden (Univ. of Maryland)

Gary Emerson (Ball Aerospace & Technologies)Gary Emerson (Ball Aerospace & Technologies)


An Overview of Deep ImpactAn Overview of Deep Impact

• Fundamental scientific Fundamental scientific objective: objective:

Probe beneath a cometary Probe beneath a cometary surfacesurface

• Two-component spacecraft: Two-component spacecraft:

Flyby spacecraft and auto-Flyby spacecraft and auto-guided, imaging impactorguided, imaging impactor

• Launch in December 2004Launch in December 2004

• Impact with comet 9P/Tempel Impact with comet 9P/Tempel 1 on July 4, 2005 will form 1 on July 4, 2005 will form ~100m-wide crater~100m-wide crater


9P/Tempel 19P/Tempel 1

• History:History:

– April 1867 discoveredApril 1867 discovered

– 1873, 1879 observed1873, 1879 observed

– 1881 close approach to 1881 close approach to Jupiter, then lostJupiter, then lost

– 1967 Recovered1967 Recovered

• Jupiter familyJupiter family

• Orbital period = 5.5 yearsOrbital period = 5.5 years

• Perihelion distance = 1.5 AUPerihelion distance = 1.5 AU

• Radius = 2.6 ± 0.5 kmRadius = 2.6 ± 0.5 km

• Albedo = 0.07 ± 0.03 (dark!)Albedo = 0.07 ± 0.03 (dark!)

• Rotation Period = ~38 hours Rotation Period = ~38 hours

• Shape, 1.3 < Axial ratio < 3Shape, 1.3 < Axial ratio < 3

• Maximum visual magnitude = Maximum visual magnitude = ~9.3~9.3

Ernst Wilhelm Leberecht Tempel(1821 - 1889)


Ground-based ObservationsGround-based Observations

• Science team is conducting a vigorous Science team is conducting a vigorous program of ground-based program of ground-based observations:observations:– Volatile outgassingVolatile outgassing– Dust coma developmentDust coma development– Jet activity and outburstsJet activity and outbursts

• Goal: Establish baselines of Tempel Goal: Establish baselines of Tempel 1’s activity for comparison to impact 1’s activity for comparison to impact and post-impact observationsand post-impact observations

• However, few observations of Tempel However, few observations of Tempel 1:1:– Lost for nearly 100 yearsLost for nearly 100 years– Rather dim, 9th magnitudeRather dim, 9th magnitude– Time on large telescopes is Time on large telescopes is

limited...limited...


Small Telescopes to the RescueSmall Telescopes to the Rescue

• Advanced amateurs and private observatories can provide Advanced amateurs and private observatories can provide good temporal coverage to supplement baselinesgood temporal coverage to supplement baselines

• Advanced observers typically have:Advanced observers typically have:

– Fast, wide-field telescopesFast, wide-field telescopes

– High-quality, commercial CCD camerasHigh-quality, commercial CCD cameras

– UBVRI filtersUBVRI filters

• Combination is good for:Combination is good for:

– Imaging and aperture photometry of dust coma (RI)Imaging and aperture photometry of dust coma (RI)

• Wide format captures field stars in same frame as Wide format captures field stars in same frame as comet, simplifying calibrationscomet, simplifying calibrations

– Imaging and monitoring of jet activity and outbursts Imaging and monitoring of jet activity and outbursts (VRI)(VRI)

• Hence, the STSP...Hence, the STSP...


2000-08-26.1 UT, 1x180s, R Filter

Wendelstein Observatory, M. Tschimmel

The Small Telescope Science The Small Telescope Science ProgramProgram

• The STSP is an E/PO project for the The STSP is an E/PO project for the missionmission

• Brainchild of Gary EmersonBrainchild of Gary Emerson

• Campaign in 2000, very successful: Campaign in 2000, very successful: – Network of 40+ observers in 12 Network of 40+ observers in 12

countries, spanning 6 continentscountries, spanning 6 continents– Observers acquired 700+ VRI and Observers acquired 700+ VRI and

300+ unfiltered, raw CCD images 300+ unfiltered, raw CCD images

• Program in hibernation for past 3 Program in hibernation for past 3 years, except for:years, except for:

– Borrelly, Wild 2, LINEAR C/2000 Borrelly, Wild 2, LINEAR C/2000 W1W1

• Re-launches this fallRe-launches this fall

• Continues through 2005Continues through 2005

2000-08-06.3 UT

The George Observatory, Fort Bend Astro. Club


STSP: Filling the GapsSTSP: Filling the Gaps

• Northern Obs: Northern Obs: Oct 2004 - Aug 2005Oct 2004 - Aug 2005

• Southern Obs: Southern Obs: Feb - Dec 2005Feb - Dec 2005

• STSP contributionsSTSP contributions

• Dust production Dust production light curve:light curve:

Large telescope Large telescope contributionscontributions

• Impact:Impact: 06:08 July 4 2005 UT06:08 July 4 2005 UT

• Perihelion:Perihelion: 08:40 July 5 2005 UT08:40 July 5 2005 UT

Impact & PerihelionImpact & Perihelion


Jet Activity and Outbursts?Jet Activity and Outbursts?

• Evidence for jet activity: 1983 Evidence for jet activity: 1983 apparitionapparition

– Upper: 3 months pre-perihelionUpper: 3 months pre-perihelion

– Lower: 1 month pre-perihelionLower: 1 month pre-perihelion

• Expect jet activity 3-4 months before Expect jet activity 3-4 months before perihelion: Mar - Jul 2005perihelion: Mar - Jul 2005

• Outbursts? Need continuous imagingOutbursts? Need continuous imaging

• Expect new active area after impact Expect new active area after impact Jets or outbursts days or weeks after Jets or outbursts days or weeks after impact? impact?

• STSP observers: Monitor for pre- and STSP observers: Monitor for pre- and post-impact activitypost-impact activity

Jean-Claude Merlin (ICQ 1983)


What We’re Looking for...What We’re Looking for...

• Advanced amateur observers with discretionary telescope Advanced amateur observers with discretionary telescope time time

• Fast, wide-field telescope systems; CCDs; VRI filtersFast, wide-field telescope systems; CCDs; VRI filters

• Aperture photometry (RI): Oct 2004 - Dec 2005Aperture photometry (RI): Oct 2004 - Dec 2005

• VRI imaging for jet activity, outbursts: Mar - Sep 2005VRI imaging for jet activity, outbursts: Mar - Sep 2005

• Narrowband images and spectroscopy also acceptedNarrowband images and spectroscopy also accepted

• Interested?Interested? Please contact us! Please contact us!

Stef McLaughlin ([email protected])Stef McLaughlin ([email protected])Gary Emerson ([email protected])Gary Emerson ([email protected])

Or visit the STSP website:Or visit the STSP website:

http://http://deepimpactdeepimpact..astroastro..umdumd..eduedu//stspstsp

• Reference: The NASA Deep Impact Mission’s Small Telescope Science Program Reference: The NASA Deep Impact Mission’s Small Telescope Science Program in the Future of Small Telescopes in the New Millenium, Astro. & Sp. Sci. 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.Library, Ed. Terry Oswalt, Vol. 289, Kluwer Academic Publishers, 2003, p. 57.

http://deepimpact.astro.umd.edu/stsp











Backup SlidesBackup Slides


Scientific ObjectivesScientific Objectives

• Primary Scientific ThemePrimary Scientific Theme

– Understand the differences between interior and surfaceUnderstand the differences between interior and surface

– Determine basic cometary properties (density, porosity, Determine basic cometary properties (density, porosity, etc.)etc.)

– Search for pristine material below surfaceSearch for pristine material below surface

• Secondary Scientific ThemeSecondary Scientific Theme

– Distinguish extinction from dormancyDistinguish extinction from dormancy

• Additional Science AddressedAdditional Science Addressed

– Address terrestrial hazard from cometary impactsAddress terrestrial hazard from cometary impacts

– Search for heterogeneity at scale of cometesimalsSearch for heterogeneity at scale of cometesimals

– Calibrate the cratering recordCalibrate the cratering record


Inter-Planetary TrajectoryInter-Planetary Trajectory


Encounter SchematicEncounter Schematic

Tempel 1Nucleus

Shield ModeAttitude through

Inner Coma

Science and Autonav Imaging toImpact + 800 sec

ITM-1 E-88 min

ITM-2E-48 min

ITM-3E-15 min

Impactor ReleaseE-24 hours

AutoNav EnabledE-2 hr

Flyby S/CDeflection Maneuver

E-23.5 hr

2-wayS-band

Crosslink

500 km


Sky PlotSky Plot

• Impact approx 06:00 - 06:30 UTC on 4 July 2005

• RA, DEC = 13:38, -9.6• Geocentric Distance = 0.894 AU• Heliocentric Distance = 1.506 AU


Earth-Based Earth-Based ElevationElevation


CO Lines Drive HRI IR CO Lines Drive HRI IR SensitivitySensitivity


Sample DataSample Data

Barringer Meteor Crater seen with Barringer Meteor Crater seen with comparable number of pixels as Deep comparable number of pixels as Deep Impact crater assuming nominal model Impact crater assuming nominal model for crateringfor cratering

MRI (full-frame)

HRI (full-frame)

E-2 hrs, 81369 km E-0 sec, 8606 km E+800 sec, 711 km

AstroCon2004 - Jul 23sam - 1 The Small Telescope Science Program Deep Impact Mission Stephanie...

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