Vomitoxin is as nasty as the name suggests. It’s produced by fungus that grows in damp conditions on corn, wheat, and other grains. It can cause an upset stomach for anything that eats it – animal or human. But it helped geologists work out the history of a meteorite from Mars, which was born in its own wet conditions.

The Lafayette meteorite was discovered more than a century ago. No one kept a record of the date, but it probably was found in 1919. A student at Purdue University in Indiana was fishing when he saw a rock splash into the mud. He fished it out and gave it to the university. Scientists thought it was an Earth rock, so they tossed it in a drawer.

Someone pulled it out in 1931, and realized it was a space rock. Decades later, it was identified as a bit of Mars. It had been blasted into space 11 million years ago.

To confirm its history on Earth, scientists studied the contaminants it picked up here. They found high levels of vomitoxin. Indiana had suffered an outbreak of the fungus that causes it in 1919 – likely confirming the story of the meteorite’s fall to Earth.

Recently, scientists studied the minerals in the rock. They found that it was born in wet conditions 742 million years ago. That suggests there was liquid water on Mars fairly recently – evidence preserved in a rock that splashed to Earth.

Mars is high in the east at nightfall, and looks like a bright orange star.

Script by Damond Benningfield