APOD opened on the web June 16, 1995. The following month on July 13, 1995 the APOD image was "A String OF Pearls" showing the broken up comet SL9. The very next day the image was of the comet fragments hitting Jupiter, APOD July 14, 1995 Comet Impacts on Jupiter. Then on the following day, The Crater Chain APOD on July 15, 1995 (Photo from 1979). The next APOD of a crater chain is this one of December 9, 1997 - Mysterious Features on Ganymede (Photo from September 6, 1996). Then a year later this one, APOD: August 5, 1998 - Ganymede: Torn Comet Crater Chain (Photo from April 5, 1997). In total APOD has shown three different crater chains from two moons of Jupiter. Unfortunately, many of those links on the APOD pages are now broken.
July 13 1995: A String Of Pearls
http://antwrp.gsfc.nasa.gov/apod/ap950713.html
July 14 1995: Comet Impacts on Jupiter
http://antwrp.gsfc.nasa.gov/apod/ap950714.html
July 15 1995: The Crater Chain (Photo from 1979)
http://antwrp.gsfc.nasa.gov/apod/ap950715.html
![Image](http://www.craterchains.com/forumimgs/callisto1_s.jpg)
http://neo.jpl.nasa.gov/images/callisto1.jpg
http://neo.jpl.nasa.gov/images/callisto.html
All though it is stated that scientists were at a loss to explain these chains of craters for fifteen years that appeared in the Calisto photos, and many others, they were at a loss to explain them for far, far longer.
![Image](http://www.craterchains.com/forumimgs/lo4_h108_2.gif)
http://nssdc.gsfc.nasa.gov/imgcat/hires/lo4_h108_2.gif
This photo taken by Lunar Orbiter 4 on May 18, 1967 of a crater chain on our moon, and is but one of the 20 plus crater chains on our moon. More than 25 years before SL9 gave it's demonstration of a true rubble pile break up.
![Image](http://www.craterchains.com/forumimgs/LPOD-2004-07-14.jpg)
http://www.lpod.org/LPOD-2004-07-14.htm
This photo is of the Davy Y crater chain on our moon, taken from earth, rivals the images of it that astronauts took. These crater chains have thus far puzzled scientists and astronomers at least from the 1920's because they had good enough telescopes back then, and today's amateurs can get images like this.
On April 22, 2002 Gale Smart (FieryIce) posted the url of the thirteen strike crater chain from APOD: 2001 December 15 at a forum we were posting at, and asked what were the mathematical odds of that? And thus was my introduction to crater chains.
Thank you so very much APOD.
Norval and Gale (FieryIce)