Last I checked, Bill Gates was worth $50 billion. If the average employed adult, who is walking in a hurry, will pick up a quarter from the sidewalk, but not a dime, then the corresponding amount of money given their relative wealth that Bill Gates would ignore if he saw it lying on the street is $25,000.

But one of the coolest things about meteorites is that most were formed four-and-a-half-billion years ago, during the birth of our solar system, when, for reasons not yet known, a cloud of gas and dust was transformed into a sun with circling planets.

In any case, the leading edge of our "on purpose" radio signals is 30 light-years away and, if intercepted, may mend the aliens' image of us based on the radio bubble of our television shows. But this will happen only if the aliens can somehow determine which type of signal comes closer to the truth of who we are, and what our cosmic identity deserves to be.

If you get asteroids about a kilometer in size, those are large enough and carry enough energy into our system to disrupt transportation, communication, the food chains, and that can be a really bad day on Earth.

The methods and tools of science perennially breach barriers, granting me confidence that our epic march of insight into the operations of nature will continue without end.

When you're enlightened, you don't have to reference other people, because you yourself are enlightened. And that's a better Earth. People can make more informed decisions politically, culturally, personally.

But to carve the Grand Canyon, Earth required millions of years. To excavate Meteor Crater, the universe, using a sixty-thousand-ton asteroid traveling upward of twenty miles per second, required a fraction of a second. No offense to Grand Canyon lovers, but for my money, Meteor Crater is the most amazing natural landmark in the world.