Encounter Observations from Earth
While most of the major observatories around the world observed the encounter with
Tempel 1, two networks of amateur astronomers had their telescopes aimed at the comet. In fact,
the 141 advanced observing teams participating in the mission's Small Telescope Science Program
(STSP) have been imaging the comet since October 2004. As of the end of July 2005, about half
the STSP teams have submitted over 360 sets of broadband red or unfiltered images of Tempel 1
to help us fill gaps in the dust production light curve as well as to monitor for other activity such as
outbursts and jets.
The science team was not sure if Tempel 1 had outbursts because the comet was never
heavily studied in the months before perihelion. However, several STSP observers recorded
outbursts from Tempel 1 on June 22 and 29, 2005. While Deep Impact instruments also recorded
the outbursts (and the navigation team reported the events first), it was good to confirm the
outbursts with ground-based observations.
Our other network, the Amateur Observers' Program (AOP) encouraged amateurs to observe
whether it was to collect "data" or for fun. While the majority of observations were from digital
cameras, several observers also made sketches and some reported their observations in text. About
65 observers (of 365 registered) have submitted over 355 observations. Observations were sent in
from all over the world -- Australia, Malaysia, Iran, Zimbabwe, Romania, Poland, Hungary,
Austria, Germany, France, Italy, Spain, Portugal, UK, Puerto Rico, as well as from all over the USA.
While the first half of the year favored observers in the northern hemisphere, the comet is now
primarily visible to observers in the southern hemisphere.
Amateur Observers' Program
This recent image from AOP observer Mike Holloway (Holloway Observatory Van Buren, AR)
was taken on 2005-07-29/02:53 UT (28 July 9:53pm CDT) and shows the dim comet. The
image was stacked on the comet so the stars appear as streaks in this image put together
from 27 exposures each lasting about 40 seconds (for a total of 18 minutes).
Small Telescope Science Program
This recent image from STSP observer Toni Scarmato (Italy) was taken on
2005-07-29/19:18 UT (effectively the next evening after Mike's image). Taken with a
larger telescope with a narrower field of view, the image includes views processed with
different methods to try to see different details in the dim comet. The image is a
composite of thirty 60 second exposures stacked on the comet (so the stars appear as
The Small Telescope Science Program (STSP) Gallery is at
and the Amateur Observers' Program (AOP) Gallery is at
Contributed by Stef McLaughlin and Elizabeth Warner