I've done all the tips, but I cant seem to get my sim abducted. He stargazes through the telescope every night from 6 to 4, he has space rocks EVERYWHERE on his lot, and there's no one else on the lot...
Make sure you have rocks on garden and 'search galaxy' in the afternoon. Go outside at 11pm and wait until 12 midnight. Works for me my sim got abducted everyday for a week :)