The camera only won’t make a picture if it’s in auto focus mode and none of the AF points register a certain amount of contrast, this can happen with less light.
Whatever aperture you set, make sure the lens is F2.8 or lower, only that will enable cross focus on XXXD series EOS camera’s.
Find an edge with contrast, point an AF-point on it, focus with flash on, lock the focus to manual, enable the self-shooter function (don’t know the term in English!).. but that should work. In case of the meteors, you can AF on a star or turn the focus to manual and screw it a milimeter off infinate.
@willbrawn Setting a low aperture would only blur the stars, it’s about the lens’ aperture. Also the bulb exposure is only handy if you want to time the lightning yourself, it doesn’t have anything to do with his camera not making pictures. And iso200 + 30sec is also not to great with stars, crank up that iso cause with 30sec stars will noticably have moved in the picture.