This camera has Video Output spec PAL or NTSC which I would be comfortable in saying is 30FPS possibly using liveview recording outputted. I found my video output produces MJPG how the nikon work check you manual. I tried to download it but have to be a registered Nikon camera owner.
How it is outputted I do not know but it would be similar to liveview recording on a Canon, I have been doing some imaging with my 450D on live view and it works better than my HD webcam. It is also easier to locate objects at higher magnifaction as well.
As you mentioned you do not want to buy any more equipment at least you can try it. There is another person on IIS using liveview to record planets as well.
My 450D using liveview of jupiter at I believe at 30FPS -
http://www.iceinspace.com.au/forum/a...se.php?a=82664
Recent Venus with my 450D -
http://www.iceinspace.com.au/forum/a...se.php?a=82661
All I need to consider is a more stable mount, better seeing an some filters.