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slash podcasts. from the BBC World Service and I'm Dr Maric Kakula public astronomer at the Royal Observatory Greenwich.

This week the story of a rock from Mars which fell in Egypt a century ago.

Since then the Nakhla meteorite has become a scientific treasure, one of the most precious

rocks on earth.

It's impossible to put a value on rocks like Narcla. Scientifically, they are priceless.

The Nakhla meerite, because it's a fresh, pristine sample of the surface of Mars,

scientifically it has to be one of the most important meteorites ever found.

And what makes it so special is that it's actually holding the secrets of water on Mars.

But what's fascinating for scientists today must have been shocking for

eyewitnesses a hundred years ago. On the 28th of June,

1911 a shower of rocks exploded in the sky over Nakhla in Egypt near the mouth of the river Nile.

As meteorite hunter Bob Haig explains, this was a rural farming community, and no one would have seen anything quite like this before.

Out of the bright clear sky is a thundering explosion and a light as bright as the sun and concussions like thunder.

And then these rocks,

...