Rocket ship = alien abduction?

No. I had none of that and yet my Sim got abducted. He lost his wife some time before and was just now beginning to date again, so he was out late when it happened. He came back dazed. His grown son, however, just a short time later, moments before his wedding, in fact, got abducted. I had the bride click on the wedding arch, since the help and the guests were already assembled and from previous experience knew the groom would be gone for some time. He was returned almost immediately, but then I realized I probably blew it. Nope. The couple got married and tried for baby on their wedding night (I was playing Pinstar's Legacy Challenge) and she got preggars. When my Heir started getting nauseous, I though he was just being overly empathetic with his wife's 'condition'. Only to realize he had gained weight. I had my very first alien pregnancy! She had a girl (I needed a boy for the Legacy) and then he had a girl several hours later, if not the next day. I had them listening to Alternative Music, too. Then he had a boy. Twins! Alien twins. So, basically they had triplets between them. Happy times, yes, it was hard, but it was fun, too. Not only that but the aliens weren't finished with this family. My Founder was a playable ghost (my first and last) and he kept getting abducted, too. Not only that but my Dad/Mom was abducted a few more times, too. I used that in my blog.

So, no, you don't need the science stuff to get abducted. Sometimes, the randomization is either on your side or it's not. I got lucky and was well-pleased.