Yes, Virginia, you can use an ordinary 8x42 binocular for astronomy." Really, I am surprised how many otherwise knowledgeable astronomers overlook this. In
astronomy binoculars, big jumbo
giant binoculars may be the current the rage, but it has not always been so. Before the advent of giant binoculars, the venerable 7x50, was "the" standard
astronomy binocular and a 7x50 or similar size binocular still has its place in binocular astronomy (no one size binocular can do it all in binocular astronomy). So, if you already own a typical
birding binocular, like an 8x40 or 8x42, do yourself a favor and turn it to the night sky to do some astronomy. You'll like what you see.