Happy Memories
August, 2011
In The Great Galactic Gold Rush (April) you note in "The Celestial Supermarket" that catching up to an asteroid doing Mach 3 to mine its precious minerals wouldn't be easy. But there is no Mach speed in space. Mach is the ratio of velocity to the local speed of sound, which in space is zero, and dividing by zero creates a black hole.Ryan LuersenWest Lafayette, IndianaYou're right. We hoped to give the casual reader an idea of how fast an asteroid might be traveling, though the speed...
