You've got the same problem as a car on Earth on a sheet of ice. There is very little friction between the wheels and the surface.

Goodness, no. The closest fragment will be about six million miles away--or twenty-five times farther than the Moon.

They could be the watering holes and fuel stations for future interplanetary exploration.

It takes 7 1/2 minutes for a signal to get from Earth to the spacecraft and another 7 1/2 minutes to get back. So, we can't joystick this spacecraft like a video game.

It's not gonna knock your socks off, and it certainly won't be the brightest object in the sky, but it'll be easily observable with the naked eye .

It looks as though some of the fragments are themselves forming their own sub-fragments.

It's an interesting object and it's raised some interesting issues, but a worrisome threat? No. We've got plenty of time.

There's a certain amount of nervousness at present. ... It's a harsh environment out there and this is not easy. We don't really know what to expect, frankly. ... It could be anything from a crater the size of a football stadium to something that's far more modest. Or the spacecraft could simply bury itself into the comet.

This is a rare opportunity to watch a comet in its death throes ? from very close range.

Sometimes, when the fragments break off, they flare up temporarily, but it usually doesn't last very long.