During these periods of re verse orretrogrademotionthey appear brighterand larger in the sky, suggestingeither that they are variable or that they have moved closer to the Earth.
They moved easily and quickly, because the moon's gravity is six times less than Earth's.
VOA: special.2009.07.15
By pairing the 3-D printed fossils with robotics, scientists are able to test how dinosaurs actually moved when they roamed the Earth millions of years ago.