minutes of terror, an autopilot plunge from space to ground, 12,000 miles per hour to full stop. and every step, flawless. you made it through that seven minutes of terror. >> yeah, i still have a few fingernails left, but they're mostly gone. >> reporter: mars is tough on spacecraft. more than half that try to get there fail. but now insight begins a two-year mission, for the first time, peering inside the red planet. and they'll do that using these sensors, david, that the team hopes will unlock some ancient mysteries about our solar system. david? >> a big day. clayton sandell, our thanks to you, as well, tonight. and there is still much more ahead on "world news tonight" this monday. cyber monday, the big deals still to come tonight. the list of what we found, coming up here. also, the new headline and the desperate search for that missing girl. police asking the public to take a good look at the sneakers she was wearing. we'll tell you why. also, oprah's loss. her mother passing away on thanksgiving. and what she said late today about her mom. and the young american killed by a remote tribe on an isolated island. police afraid they were about to be attacked, too, as they tried