Extraterrestrial Footprints

Over two billion years ago, a hurtling planetary body smashed a gaping hole into Earth’s crust in South Africa, creating our planet’s oldest identified impact crater: Vredefort. As recently as 2009, collisions with earth have continued to influence Earth’s surface structure. Intrigued by the chemical processes involved with impact cratering, geology student Terik Daly is using his Barry M. Goldwater scholarship, which awards up to $7,000 dollars to its recipients, to fund his research in this area.

Daly has loved geology ever since he was a toddler.

“I got into geology when I was probably like two,” he said. “I loved dinosaurs growing up, and I had a volcano phase when I was in second or third grade. Then there was an earthquake phase around the end of junior high.”

It wasn’t until he watched a documentary on Gene Shoemaker’s pioneering research in impact cratering, however, that he got interested in this natural phenomenon.

Impact cratering happens because space is full of debris, which includes tiny particles only one tenth of a millimeter across and enormous asteroids 15 kilometers long. These planetary bodies speed through space and eventually cross paths with each other as well as larger bodies, such as the planets and moons in our solar system. When these bodies collide they produce craters that can be as large as 250 kilometers across, like the Sudbury Basin in Ontario, Canada, and even 300 kilometers across, like the Vredefort structure.

Daly is currently studying this same cratering, but on a micro scale in the lab. Using powerful microscopes, he can observe tiny craters on dust particles. By studying the effects of collisions on samples of this size, Daly hopes to expand these applications to larger objects. In particular, he is determined to one day identify what sort of heavenly body made any given crater on earth by analyzing the chemical composition of samples gathered from that location.

By Natalie Rice Posted on