Discussing Lagrangian (Lagrange) points, orbits and gravity. Speaking is Professor Mike Merrifield. Animations by Pete McPartlan. Pete's website is: http://www.petemcpartlan.co.uk/ Professor Merrifield tweets at https://twitter.com/ProfMike_M Deep Sky Videos is our astronomy channel - http://www.youtube.com/DeepSkyVideos Visit our the Sixty Symbols website at http://www.sixtysymbols.com/ We're on Facebook at http://www.facebook.com/sixtysymbols And Twitter at http://twitter.com/#!/periodicvideos This project features scientists from The University of Nottingham Sixty Symbols videos by Brady Haran