They had no idea of the great volcanoes and canyons of Mars, which make Mount Everest look like a worn hillock and the Grand Canyon like a roadside ditch.

• 他们对火星上的巨大火山与峡谷毫无头绪，相较之下地球上的圣母峰看起来就像个小土丘，美国的大峡谷则如同路边的小水沟。