The Kitt Peak National Observatory's 2.1-meter telescope observed comet
Tempel 1 on April 11, 2005, when the comet was near its closest approach
to the Earth. A pinkish dust jet is visible to the southwest, with the
broader neutral gas coma surrounding it. North is up, East is to the left,
and the field of view is about 80,000 km (50,000 miles) wide. The Sun was
almost directly behind the observer at this time. The red, green and blue
bars in the background are stars that moved between the individual images.
This pseudo-color picture was created by combining three black and white
images obtained with different filters. The images were obtained with the
HB Narrowband Comet Filters, using CN (3870 A - shown in blue), C2 (5140
A - shown in green) and RC (7128 A - shown in red). The CN and C2 filters
capture different gas species (along with the underlying dust) while the
RC filter captures just the dust.