NASA scientist Bill Cooke is shooting marbles and he's playing "keepsies." The prize won't be another player's marbles, but knowledge that will help keep astronauts safe when America returns to the Moon in the next decade. Cooke is firing quarter-inch diameter clear shooters – Pyrex glass, to be exact – at soil rather than at other marbles. And he has to use a new one on each round because every 7 km/s shot destroys his shooter.
Can we detect asteroid impacts with rocky extrasolar planets? Sixty-five million years ago a chunk of rock and ice perhaps 15 kilometres across collided with the Earth and wiped out many creatures, including the dinosaurs. This impact, known as the Chicxulub impact, must have created a spectacular flash. Was it bright enough to be detected as far away as Sirius? How many impacts like this are occurring in our region of the Milky Way? Have we any chance of detecting these impacts? These questions can be answered, in part, with a little mathematics, a few facts from astronomy and the audacity to assume that our solar system is “typical”.