Why do you think Skander started this correspondence with Pen Pal?
Skander is a curious one, whose thirst for knowledge is much more as compared to any common being. He tried to experiment on himself without fearing the risks involved. Therefore, he is a daring person. Out of curiosity and insatiable hunger to know and understand he must have tried to reach out to beings on other planets. It is possible that he must have tried to reach out other parallel universes too.