Some suggestions to jump start a net or even a nation wide on-line/on-air club.
You've made the first step. A place, it seems to me to try is also is on a local level. Check with a local club and ask them if you can put an "ad" in their news letter to see if there is any members that are also active radio amateurs. If so, join, or join anyway. There is a club or two that have combined both disciplines. They control and receive data from a remote observatory via Amateur Radio. I don't remember the name, I think it was in the Pacific Northwest somewhere. Don't forget club and non-club affiliated websites. Astro Tom ( http://www.astro-tom.com
) is one of the biggest. It's based here where I live. Open an account and post the same notice in their forums. If you start a net, ask the website owner/s if they will post a small banner ad about it free of charge.
Try on line searches and email enquirees, perform a search for licenses with the word astronomy attached from the Callsign Database at QRZ for example and use a mass emailer to broadcast the times/dates of the net, but only once per address. No one likes spam, even for a good legitimate purpose.
Join or start an interdisciplinary Yahoo or Google group.
Post a notice of a desire to meet others with the same interests on your profiles on QRZ, Eham and HamCall, for example.
As for me, I am myself but I live out west so I could join a net depending on the band conditions. There is also my neighbor to the east of me, Ron, KB6WBO, though I don't know if he's the "net" type. My best possibility would be 40M and 75M because my antenna is not much good at 20 and up. If you get something going post a notice here. I've also heard non-net QSOs of people discussing Amateur Astronomy as well, so they're out here.
And would it not be cool to be at a interdisciplinary club star party with most members having instant access to each other via HTs. Or, even include a third discipline, computer science via a wireless network to share photos and ideas in text.
See you down the log...