There's a long list of technologies that have now made it possible to carry out very precise search efforts in the deep sea.
Robert BallardThe fact that this chain of life existed [at volcanic vents on the seafloor] in the black cold of the deep sea and was utterly independent of sunlight - previously thought to be the font of all Earth's life - has startling ramifications. If life could flourish there, nurtured by a complex chemical process based on geothermal heat, then life could exist under similar conditions on planets far removed from the nurturing light of our parent star, the Sun.
Robert BallardYou don't go to Gettysburg with a shovel, you don't take belt buckles off the Arizona.
Robert Ballard