come down to earth—(also: come back to earth) stop daydreaming; return to practical realities (especially unpleasant):
- Now, Virgie, come down to earth and give me the low-down. What’s happened to Mrs. Bedford’s diamonds?
go to earth—(also: go to ground) go into hiding; put oneself out of sight:
- The policeman … turned back to assist his colleagues in finding Barbury, so mysteriously gone to earth.
See also: drop from the skies / fall to the ground.