There is a warming cooling pulse in Earth’s life exemplified by tracks left from ancient glaciers to deserts once flush with flora and fauna. When did all this occur and why? Here’s what I think: Moon orbits Earth, Earth orbits Sun, Sun orbits Milky Way, Milky Way orbits ??? Each event takes longer to complete. For the Sun to orbit the Milky Way it takes roughly 28 million Earth years. In fact, I don’t believe the Sun has made more than 20 orbits since Earth was created. The problem arises when trying to determine what occurs with other stellar objects in our Galaxy during the Sun’s orbit. For example, to blame global warming on puny little humans is most likely a fine case of naiveté. I would like to look with geologists at our sedimentary layers at 28 million year intervals to see possible repeat activity. Unfortunately, finding something caused during one of the 20 Sun’s Galaxy orbits among the millions of Earth’s Sun orbits and determining which was which is near impossible. However, to rule out the Sun and it’s travel may remove a signature from the portrait. As our Galaxy nears another, when they pass does ours bounce away? Did the shock start Continental drift? Do all stars in our galaxy orbit in the same direction? Is one star orbiting faster than another? Hubble should be able to answer these questions and help put new light on our Solar System’s future. To set some idea of what vast fluctuation can occur look at Earth’s annual weather. Predict what will happen six months from now! Impossible! However, afterwards we know what happened and why it happened. So when scientists analyze space what questions are they asking. More importantly, what questions are they able to answer.