Scientific impact

John Spray, left, director of the Earth Impact Database, and Beverley Elliott, data manager, examine a map of meteor impacts. David Smith / Telegraph-Journal photo.Hidden away in a corner of the Forestry & Geology Building at the University of New Brunswick's Fredericton campus is a research centre of astronomical proportions.

John Spray is a geologist by trade, but upon his arrival at the University of New Brunswick in 1986, he started focusing on impact craters - which has broadened his research scope to include everything from Martian rovers to satellite infrastructure.

Currently, Spray is the Director of UNB's Planetary and Space Science Centre (PASSC) on the Fredericton campus. The centre currently has 15 people under its wing and is growing.

Graduate students working at the PASSC don't just observe from afar - some are directly studying lunar soil and Martian meteorites affected by the impact of asteroids and comets.

"Impact is a dominant process on most other planetary bodies, like the moon and Mars, whereas on Earth its effects have been hidden," says Spray. "Our impact knowledge is actually applicable to other planetary bodies, but also to Earth's lost past - our active planet having destroyed most of its cratering history due to plate tectonics."

Spray and his group also work directly on Earth - the professor's expertise on the Sudbury, Ont. crater has led him to be featured on the recent History channel How the Earth was Made Asteroids series.

Sudbury is a major mining community built on one of the largest impact craters in the world.  "Understanding the impact process in Sudbury is very important for understanding where the metal deposits lie," says Spray. Currently, Spray's group is leading a 10-year research program dedicated to the 90 km diameter Manicouagan crater in Quebec.

Spray has also been featured on Geologic Journey and David Suzuki's The Nature of Things.

Exploring the unknown

PASSC is working directly with world-renowned space agencies, including the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). His work with the groups will see UNB directly involved with two missions to Mars in the near future.

"I first got into studying impact craters on Earth and expanded that to looking at impact craters on other planets like Mars," says Spray.

He's currently on the science team of NASA's Mars Science Laboratory rover mission to Mars, which is due to launch in 2011.

"It's a large rover about the size of a small car, which is big as rovers go. I'm on the Canadian team that is providing one of the analytical tools for that rover. We will be directly involved at UNB with that mission."

He's also on the science team with ESA for another mission called ExoMars. Due to launch in 2016, Spray is the only Canadian member of a Swiss-based science team, which is developing a close-up imaging system for the mission.

Because of his involvement in the missions, both graduate and undergraduate students at UNB will have the opportunity to directly contribute to these space missions through PASSC - a chance that isn't available at most universities.

From macro to micro

Studying impact craters has led Spray and his colleagues to examine shock waves at multiple levels. Micrometeorites, about 1mm in diameter, pose a major threat to any materials outside the Earth's atmosphere - in particular, satellites and spacecraft.

"We've been studying impact and we understand shock wave materials behaviour, so we're applying that knowledge to help design shielding to protect space infrastructure," he says.

"Micrometeorites are these little guys who are left over from the formation of the solar system who never coagulated to form bigger bodies. They fly around at an incredible 25-70km per second and can do a lot of damage if they hit something in their path," says Spray.

His research will help protect bodies in space from micrometeorite-related damage by investigating the use of thin, light shields for satellites and spacecraft. He's helping to design an outer skin that minimizes the damaging impact of micrometeorites.

"It's a separate layer. When the micrometeorite hits this, it fragments into smaller pieces and they spray onto the inside, but basically their energy is dissipated. Sometimes we deploy two shield layers so the micrometeorite never even touches the hardware."

Spray, who holds a Tier 1 Canada Research Chair in Planetary Materials, has seen five of his graduate students become professors at other universities after working with him.

"What my students do in their careers after leaving UNB is an important gauge of my performance as a supervisor and mentor," says Spray.

"I learn as much from my graduate students as they do from me, and I enjoy the training and facilitating roles. Hopefully, the upcoming Mars mission science will give our students exciting future job opportunities with NASA, ESA, the Canadian Space Agency and related science and technology industries."

Contributed by Josh O'Kane. This story was made possible thanks to the financial support of the UNB Associated Alumni