On Oct 10, 6:58 pm, "canopu...@yahoo.com
One last parting question for the LCROSS scientists before I sign off
I would like to roughly estimate the height of the actual plume using
three graphs displayed at the LCROSS post-impact press conference.
What is are the equivalent time units in seconds for the Data Handling
Unit (DHU) timestamp displayed in three graphs at the LCROSS post-
impact press conference of 10-9-2009?
At minute-seconds 10:42, 11:43 and 11:52 of the press conference
video, three radiance graphs are displayed.
From the graphs, it appears the plume was first detected by
shepherding spacecraft at 0.0003 to 0.0005 DHU time units before
Assuming the actual impact occured at the pre - event published values
of 2.5 km /s and an angle of about 65 degrees, if the absolute value
of DHU timestamp units is known, then the height of the plume can be
estimated. In t seconds the LCROSS shepherding satellite would
travel t secs, a distance (d) of t secs x 2500 meters / sec. With
respect to a normal surface, that distance represents the hypotenuse
of a right - triangle, the height of which is sin (65 degrees) x d.
If the absolute time units of the DHU timestamp can be determined in
second units, then an estimate of the height of the LCROSS plume in
meters could be made using -
h meters = Sin[ 65 Degree] * 2500 meters/sec * t secs
h = 2265.77 x t
Ditto to JHJ comment - great outreach program.
Clear Skies - Kurt
LCROSS Post-Impact Press Conference archvied on YouTube