Information for Deep Impact Observations from Table Mountain

June 22, 2005
  • The actual time of impact (TOI) of Deep Impact was,

    05:52:24.0 min UT 4 July, or
    23:52:24.0 min MST 3 July, Earth-receive time.
    Distance from Earth will be: 0.90 AU

  • The comet's coordinates at that time were,

    RA: 13h 38m
    Dec: -09 35'

  • As seen from DSES, Tempel 1 was at,

    Alt: 15d 14m
    Az: 242d 53m

  • The elevation of the horizon (due to mountains) in the direction of the encounter (Az: 242d 53m) will be,

    Horizon elevation: 3.6 degrees

    In other words, the mountains will NOT block viewing the Deep Impact event from the upper dish.


Additional Information
  • The highest horizon (due to mountains) as it appears to the DSES upper dish is,

    Highest horizon: 5.1 degrees

  • Complete horizon data for the DSES upper dish in 5-degree increments,

    Plot:  http://deep-space.org/udprofileplot.html
    Data: http://deep-space.org/udprofiledata.html

  • Chart of trajectories of 9P/Tempel 1, the Deep Impact Flyby Spacecraft, and the Impactor,

    Tempel-Spacecraft-Impactor.html

  • Sky chart of 9P/Tempel 1 showing DSES horizon,

    tempel1chart.html at TOI
    tempel1chart.html at TOI +1 hour

  • How fast will 9P/Tempel 1 be moving at TOI?

    dRA*cosD = 66.07 arcsec/hr
    d(DEC)/dt = -58.81 arcsec/hr

  • How bright is 9P/Tempel 1? The JPL ephemeris (below) shows T-mag (the comet's approximate apparent visual total magnitude)
    is as follows, but actual brightness may differ,

    T-mag = 9.38 on date above
    T-mag = 9.49 on July 4th

  • How much energy will result from the impact?

    820 pounds = 372 kg
    23,000 mph = 10,000 m/s
    1 mJ = .000239 tons TNT

    KE = 1/2 mv^2 = .5 * 372 * (10,000)^2 * 10^-6 = 18600 mJ = 4.45 tons TNT

  • Encounter Ephemeris: Following is a 1-minute interval ephemeris with RA and Dec plus Alt and Az computed for the upper dish location. The data spans about 1 hour before and 3 days after the TOI,

    http://deep-space.org/eph/temp1impact.html

  • Observational Ephemeris: Ephemeris data at 10-minute intervals for Deep Impact and 9P/Tempel 1 are listed below. Each includes Azimuth and Elevation computed for the DSES upper dish and other standard parameters.

    http://deep-space.org/eph/tempel1obs-4.shtml
    http://deep-space.org/eph/deepimpactobs-4.shtml

    All ephemerides were computed on JPL Horizons assuming E-Long: 254.767970 deg, Lat: 40.1484 deg, Altitude: 1.666 km
TM 6/23/05
Plot of 9P/Tempel 1 trajectory at the predicted TOI, 05:52 min UT 4 July. The pink dotted line is the horizon of the DSES upper dish. Radio sources are shown as green circles, pulsars are yellow. The fine white dotted line is the ecliptic, and the dotted square grid is elevation and azimuth.