It's unknown for now. We are not capable of any noticeable time traveling at this age. Even tho, time is proven not absolute, and each of us still experiences time differently but we can't notice that at our human's scale.
Traveling to another parallel timeline sounds like an idea taken from the general public's understanding of String Theory which has a grand mathematical structure beneath but our technologies have not been able to test it just yet.
However, I think saying impossible is a little bit hasty, natural science is designed to constantly seek for new "truths", it takes a lot to say something is absolutely impossible in any scale, any frame of reference.
Best of luck;