Gleaned from astronaut Kathryn Thornton, who flew aboard the space shuttle four times:

If the Earth were the size of a basketball, spacecraft in orbit wouldn’t be more than a quarter to a half inch off its surface.

Thornton’s point: humans aren’t exploring any more. They’re stuck repeating experiments in an environment they already know. Most astronauts, of course, are strongly in favor of President Bush’s plan to send astronauts back to the moon and then on to Mars. Many scientists are not, which makes her presence at a AAS meeting particularly intriguing.