It's long been believed that truckloads of unsold cartridges were buried in a New Mexico landfill in late 1983, covered over by rubbish and concrete. (The game itself was not lost and is available today on emulators. You can find lots of Let's Play videos on YouTube... all of which do back up the assertion that it's a truly terrible game.)
Recently the city granted permission for a crew to dig there and, sure enough, the legends were true...
Old E.T. cartridges are being pulled up, along with other Atari overstock. Amazing!