For example, we do now know that habitable environments are very common in the universe. It is reasonable to generalize from here to a truly gargantuan number of habitable environments across the ...

are we alone in the Universe? In a Universe that contains billions upon billions of stars and planets, what is the chance that life will form on any of these planets? Of this life, what percentage ...

Given the vastness of the universe and the probability of other ... our history—the desperate yearning to know if we are alone. Terrifying as it is to think there may be advanced civilizations ...

When a boy named Elliott found an alien in the classic 1982 film "E.T." it offered easy answer to the question on every astronomer's mind: Are we alone in the universe? In reality, however ...