Scientists suspect Mars’ surface is littered with HUGE sinkholes caused by widespread subterranean ice – RT World News
:quality(85)//cloudfront-us-east-1.images.arcpublishing.com/infobae/GJFOMCQO2FHHTDPHMPUH227NMA.jpg "Elon Musk proposes to build subterranean tunnels in Miami to eliminate traffic jams")