Gravity moves at the speed of light and is not instantaneous. If the sun were to disappear, we would continue our elliptical orbit for an additional 8 minutes and 20 seconds, or the same time it would take us to stop seeing the light (according to general relativity). – WTF Fun Facts
Source: http://math.ucr.edu/home/baez/physics/Relativity/GR/grav_speed.html