Mountain View, CA: What's up with that big plane that flies around out of Moffet(?)

It’s a big, four-prop military plane that flies low circles over the South Bay. I’ve been seeing it for years. I haven’t seen it take off or land, but it seems to be coming and going from Moffet Field. Any information on it?

Does it look like this?

Do they still fly P-3s out of Moffet? Is it one of the Ames Research Center’s test aircraft?

That looks like it. So it’s an Air National Guard plane. I’m guessing that most of the time I see it fly around it’s for pilot training.

Thanks.

That’s a baby…keep your eyes peeled for the Anatov An-225 that’s been known to drop by there on occasion. http://en.wikipedia.org/wiki/Antonov_An-225

Google Atmosphere, taking pictures for their cloud map.