Observation: I can’t see a thing.Conclusion: Dinosaurs.

The suppression of uncomfortable ideasmay be common in religion and politics, but it is not the path to knowledge; it has no placein the endeavor of science.

Everything not forbidden by the laws of nature, he assured her - quoting a colleague down the hall - is mandatory.

We will know which stars to visit. Our descendants will then skim the light years, the children of Thales and Aristarchus, Leonardo and Einstein.

Birds know, better than humans, not to spoil the nest.

Even if the aliens are short, dour, and sexually obsessed—if they’re here, I want to know about them.

There is perhaps no better a demonstration of the folly of human conceits than this distant image of our tiny world.

Centuries hence, when current social and political problems may seem as remote as the problems of the Thirty Years' War are to us, our age may be remembered chiefly for one fact: It was the time when the inhabitants of the earth first made contact with the vast cosmos in which their small planet is embedded.

Imagine we could accelerate continuously at 1 g-what we're comfortable with on good old terra firma-to the midpoint of our voyage, and decelerate continuously at 1 g until we arrive at our destination. It would take a day to get to Mars, a week and a half to Pluto, a year to the Oort Cloud, and a few years to the nearest stars.