In every case, it is because they either are holding on to a religion or they are not experts. It could be the standard model, it could be heliocentrism (which in fact has never been observed), it could be their belief that Jesus is GOD, affecting them.
Whatever the case, the fact that you haven't seen this means that YOU also are a member of the religions in questions. Be a true scientist and scrutinize every model. Did they measure the mass of the planets. Nope. How deep of well would be required to measure 93M miles of distance to the sun on Earth?
More pertinent to your question is the fact that there are always an infinite set of lines that go through any finite set of points (the scientist's observations and data). So this is how experts disagree: they see the same points, but they've drawn a different line through them.