From NASA press conference:

Moon rivers, wider than a mile are expected We’ll be drilling them in style some day Oh, dream investors , you heart breakers Wherever you're goin', I'm goin' higher Two drifters, off, we’ve seen the world There's such a lot of space to see We're after the same spectrums end Waitin' 'round the gravitational bend My exospheric mass spectrometer friend Moon river and me