asteroids

The best candidate for a binary crater on Earth today is the Lockne crater in Sweden and a smaller crater nearby called Målingen. “We dated these structures very exactly and saw that they formed at exactly the same age,” about 450…

How much do we need humans in space?  How much do we want them there?  Astronauts embody the triumph of human imagination and engineering.  Their efforts shed light on the possibilities and problems posed by travel beyond our nurturing…