Key to return to Earth?

Is there a shortcut key combination that will always get you back to the "normal" view of being on Earth looking up at the sky? While practising using Nightshade, travelling to the Moon or a planet etc I sometimes get "lost" and cannot tell from the screen where I am! I think Celestia has "HG" or something similar that will always take you home - is there anything like that in Nightshade?