I need help identifying a movie which I've been looking for for the last maybe 10 years, without any success. The information I remember about the movie are as such:
The father was conducting some experiment and was this way transported to this other dimension/world, and when the police investigated his lab, a woman came with the results from the lab which said they found a dust-like substance that was some billion years old, with the test's accuracy being at some million years give or take.
The father's son and daughter somehow went to this other world, and there were greeted by someone I think, but they definitely saw 3 suns there when they arrived.
That someone who greeted them took them to the place where their father was held, it was a state building where everyone was supposed to act like robots, soulless and such and so did the children in order not to be caught.
The children found their father, and that's either where my memory ends or I stopped watching.
I watched this movie when I was a kid, on the early classes of elementary school I believe. I am currently 22 years old. However, I'm not entirely sure whether it was in English, or I watched it on German satelite tv. But a lot more possible that is was in English.
Thanks in advance to anyone that takes the time to help me out even in the slightest.