Geology en The oldest rock in the world tells us a story It's hard to imagine how this teeny little rock — it's not even a whole rock, it's just a grain, a miniscule droplet of mineral barely the thickness of a human hair — could rewrite the history of our planet. But that's what seems to be happening.<p>What is this? It's a zircon, from the Persian word "zargun" meaning "golden colored," an extremely durable mineral found all over the world. This one turned up in a dry, hilly region of Western Australia. It was sitting inside a larger rock, and when scientists checked, it turns out this little grain formed around 4.4 billion years ago. Sat, 12 Jan 2013 19:56:02 +0000 Robert Krulwich 7545 at The oldest rock in the world tells us a story Mima Mounds continue to mystify scientists <p></p><p>There&rsquo;s a large swath of native prairie southwest of Olympia that&rsquo;s very strange looking. So strange, in fact, that some have even said it was created by aliens.&nbsp;</p><p>What makes it strange are &ldquo;things&rdquo; called <a href="">The Mima Mounds</a>.</p><p>We can tell you some things they are <em>not</em>, but we can&rsquo;t tell you what they <em>are</em>. In fact, people have been trying to figure them out for centuries.</p><p>&ldquo;It&rsquo;s probably one of the most poorly understood phenomena in earth science,&rdquo; says Paul Butler, professor emeritus of Earth Science at the Evergreen State College.</p><p><strong><a href="">Read more on I Wonder Why ... ?</a></strong></p><p> Fri, 13 Jan 2012 12:30:00 +0000 Bellamy Pailthorp 3678 at Mima Mounds continue to mystify scientists