No other planet in the solar system is a suitable home for human beings; it's this world or nothing. That's a very powerful perception.

Next quotes

• Carl Sagan:

  There is a wide, yawning black infinity. In every direction, the extension is endless; the sensatio

• Carl Sagan:

  Even these stars, which seem so numerous, are as sand, as dust - or less than dust - in the enormit

• Carl Sagan:

  We are not without empathetic terror when we open Pascal's 'Pensees' and read, 'I am the great sile

• Carl Sagan:

  We start out a million years ago in a small community on some grassy plain; we hunt animals, have c

• Carl Sagan:

  We hunger to understand, so we invent myths about how we imagine the world is constructed - and the

• Carl Sagan:

  Today, we're still loaded down - and, to some extent, embarrassed - by ancient myths, but we respec

• Carl Sagan:

  We are the representatives of the cosmos; we are an example of what hydrogen atoms can do, given 15

• Carl Sagan:

  The boundary between space and the earth is purely arbitrary. And I'll probably always be intereste

• Carl Sagan:

  I've written a number of books that have to do with the evolution of humans, human intelligence, hu

• Carl Sagan:

  Most of the people that I deal with are human. So I've had a lot of experience with that.