A NASA rover zapped a rock on Mars — and found a gemstone hiding inside

Professor Pip stood on a pretend-Mars — a bumpy patch of red dirt in the corner of his garden — and adjusted his slightly crooked spectacles. "Ah! Look at this, my friends. Rusty. Dusty. And full of surprises." He patted his bulging green lab coat pockets and pulled out a magnifying glass, a chunk of pale rock, and a very small flashlight.

Mia and Leo sat cross-legged in the dirt beside him. A little robot rover Pip had built out of cardboard beeped between them.

"On the real Mars," said Pip, his tail swishing behind him, "a NASA rover shone a laser at rocks that looked very boring. Grey. Pale. Uninteresting. And do you know what shined back?"

"A dinosaur?" Leo guessed hopefully.

"A gemstone," Pip whispered, eyes twinkling. He clicked on the flashlight and shone it through the pale rock in his paw. A tiny red-pink glimmer sparkled out the other side. Mia gasped.

"Watch closely," said Pip. "Light did the same thing on Mars. The rover's laser buzzed the rock — ZAP! — and the tiny bits inside the rock glowed a very special glow. Every mineral glows its own way. Scientists know each glow like you know your friends' voices from far away."

"So they heard the rock's voice!" said Mia.

"Precisely right!" Pip beamed. "And the voice they heard belonged to a mineral called corundum. On Earth, when a little bit of chromium sneaks into corundum, it becomes a ruby. If bits of iron and titanium sneak in, it becomes a sapphire."

Leo's mouth dropped open. "So Mars has rubies?!"

"Not big shiny ones you could hold," Pip laughed, "but teeny, tiny grains — smaller than a speck of sugar. And here's the wondrous part: corundum only forms when rocks are squeezed and heated to extremely big temperatures. Jezero Crater was made billions of years ago when an enormous space rock slammed into Mars and made a hole 45 kilometers wide."

"Like a giant hammer!" said Mia. "That would squish the rocks!"

"Exactly right! The impact could have cooked the ingredients that made the gems." Pip looked up at the wispy afternoon sky. "So a rock that looks boring on the outside can be hiding the memory of the day the sky fell down. Isn't that curious?"

He handed Mia and Leo each a small pebble. "Now you try. Find the most boring rock in the yard — and tell me what its story might be."