"Kepler's laws don't account for the subtle gravitational perturbations that planets exert on one another. By rearranging the planets, you perturb these perturbations, and it's not obvious what would happen."
"As next-door neighbors in the inner solar system, probably formed about the same time, why isn't Mars more like Earth and Venus in size and mass? A new paper provides the first cohesive explanation and, by doing so, reveals an unexpected twist in the early lives of Jupiter and Saturn as well."
"We've featured many space images here on Universe Today that have been produced by imaging enthusiasts who take raw images from a mission or spacecraft and refine them into what many consider works of art. Michael Benson has taken this activity to a level 'above and beyond' by creating exhibits, books, and movies portraying the images taken by our robotic emissaries to the solar system."