There is a poem by John Masefield that I think encapsulates the emotion of those who search for other Earths. The title is "The Unending Sky" and here it is -
I could not sleep for thinking of the sky,
The unending sky, with all its million suns
Which turn their planets everlastingly
In nothing, where the fire-haired comet runs.
If I could sail that nothing, I should cross
Silence and emptiness with dark stars passing,
Then, in the darkness, see a point of gloss
Burn to a glow, and glare, and keep amassing,
And rage into a Sun with wandering planets
And drop behind, and then, as I proceed,
See his last light upon his last moon's granites
Die to a dark that would be night indeed.
Night where my soul might sail a million years
In nothing, not even death, not even tears.