The festival will be a celebration of all things astronomical with a series of lectures by astronomers and scientists.
Topics will range from the history of astronomy to the science behind the Hubble space telescope's most iconic images.
The h
ighlight will be a talk on Sunday (September 7) at 1pm from legendary broadcaster and writer Sir Patrick Moore on his exploits observing the moon.
Sir Patrick, now 85 and still living at his home in Selsey, West Sussex, told the Gazette he was looking forward to the festival.
He said, "It should be a great success. I'm most looking forward to meeting old friends."
Sir Patrick, who has presented BBC's The Sky At Night for more than 50 years, said the moon still fascinated many people.
He said, "It's a world we can see and a world we can reach.
"But it's a world that we still don't know much about. There is lots to discover about it.
"I'm sure man will go back there one day."
Copies of a fictional book Sir Patrick wrote, Ancient Lights, will also be on sale at the festival.
It is the first new non-astronomical, fictional book to be released by Sir Patrick in more than 30 years.
Famous astronomers Nigel Henbest and Heather Couper will also be giving a lecture and there will lots to do for all the family, including rocket making, tours of the observatory's famous telescopes, stalls from local astronomy societies, tours around the Space Geodesy Facility, trade stands and informal beginners' workshops by Sky At Night Magazine.
For more information on the festival, visit www.the-observatory.org/astro_festival.htm or phone 832731.
• For more on Sir Patrick Moore's official memorabilia, visit www.star-distribution.co.uk.