The Austin Skeptics Society celebrated the 200th birthday of Charles Darwin last Thursday. The cake was courtesy of Taysia and the Darwin finger puppet is mine (from the Darwin exhibition at the American Museum of Natural History in NY in 2006).
Hall of Saurischian Dinosaurs, American Museum of Natural History, August 2006. T-Rex in foreground and Apatosaurus in the background.
I figured that some of the largest things to ever roam the planet was a good way to celebrate the 200th birthday of Charles Darwin, along with my favorite quote from On the Origin of Species (which was published 150 years ago this year):
... whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."
Pluto, July 1997. 30-inch telescope at McDonald Observatory
This is a stack of 4 images taken over a 5 day period. If you look to the bottom of the frame, you will see 4 dots - red, green, blue and yellow, each representing Pluto on a different night. Three look regularly spaced with the red dot is further away. There would have been a spot between the red and green, but that night was cloudy, so no observation was made.
How the composite image was made:
If you look at the upper left and lower right corners, you will see two bright stars, which helped to find the field in each of the images. I took three of the frames and pulled them into Photoshop, each in a different channel. When the star images lined up, they appeared white, but the object that was different on each of the frames (Pluto), appeared as a red, green and blue dot from the object's image in each of the channels.
The fourth image was stacked (as a greyscale) over the combined image from above. The two images were added, and the fourth image of Pluto was hand-colored yellow.