Phil sent me a rock. No, seriously – a space rock! I published the first half of his accompanying letter in tonight’s report, My Mighty Meteorite. This is the second half of his letter to both Ponzi and myself:

What you have here is a piece of shrapnel from this meteorite. Its composition is about 91% iron, 7.1% nickel, 0.46% cobalt, 0.26% phosphorus, and about 1% sulfur. There are trace amounts of gallium, germanium, and iridium (that last was the key element that lead scientists to understand that the dinosaurs were wiped out by a similar but much larger blast).

Most meteorites are stone. They come from asteroids in the belt between Mars and Jupiter. When a large body forms in a solar system, all the stuff making it up is at first mixed, like batter. But when it gets big enough, the heavy stuff – the metal – sinks to the center. So you need a big asteroid for that to happen, bigger than the Moon, so that its gravity is strong enough to differentiate it. Then it has to suffer a mighty blow from another huge asteroid, disrupting it, blowing it into billions of pieces.

What you’re holding in your hand is a piece of metal that was once deep within the core of a planetary-sized body that was destroyed by the impact of another planet-sized body, 4 billion years ago. It orbited the Sun, relatively untouched all that time, until that fateful day 30 millennia ago. It’s a piece of outer space brought to Earth in a fiery, violent decent that ended in cataclysm.

And now it’s yours.

[The first half of Phil's letter has been published elsewhere - and if you haven't figured it out by now, I'm very thankful for his gift. It's kinda like space copralite?]

• Asteroids!
• A Planet Nowhere Near Mars
• Planet Pluto
• SETI Hears a Who?
• Apollo UFO