What Happens to the Curved Space around a Massive Object that has been Destroyed?

According to the General Theory of Relativity the space is curved around a massive object. Then, after the planet explodes (due to internal forces) or destroyed (because of external forces) does the space around it still remain curved or does it straighten back to flat? How would the disappearance of a planet impact the other planets? Will its orbit be occupied by another cosmic object that might be forming from residues that fall into this orbit? If space is curved around a star and forms tracks that planets travel following these tracks as rail-roads, why not other (small, or medium, or massive) objects are falling into these tracks and traveling around the star on the same orbits?