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Spray, Elliott and Thompson team up with NASA


A planetary geologist by trade, Spray and his fellow researchers at UNB are responsible for one of the Mars rover's key instruments - the Alpha Particle X-Ray Spectrometer (APXS).

Having worked on the Mars Science Laboratory (Curiosity’s official name) for the past several years, Spray was anxious to start analyzing the data. As the director of the University of New Brunswick’s Planetary and Space Science Centre, Spray is among those who believe that the truth behind Mars’ mysterious and potentially life-supporting past will finally be unearthed as a result of this mission.

A planetary geologist by trade, Spray and his fellow researchers at UNB are responsible for one of the Mars rover’s key instruments - the Alpha Particle X-Ray Spectrometer (APXS).

"The APXS instrument is positioned at the end of a two-metre long arm when extended," says Spray, "and it is accompanied by a microscopic imager, which is akin to using a hand lens to look at things. The APXS can be used to determine the chemistry of the materials (dust, soils and rock) we are studying."

In addition to equipping the rover with the APXS Spectrometer, Spray and his UNB colleagues Beverley Elliott and Lucy Thompson will also study the geology of the site where the Rover landed - the 155 km-diameter, Gale impact crater.

Spray, Elliott and Thompson will examine the geology of the site to figure out how and when the crater was formed, as well as helping to identify the materials it now contains.

"As geologists, we have to interpret the context of the rover and help to work out what happened on Mars around 3.8 billion years ago," says Spray.

As it would the layers in a cake, the Mars rover will climb up the 5-km high mound that defines the centre of the crater, studying the different materials and linking them to processes that formed them, which may have generated river, lake, volcanic and impact products over billions of years. 

"The basal layers would have been formed first, and over time additional layers have accumulated to make a pile. Each one could represent a few million years in time. The rover is going to climb up these layers and study all the way back from early Martian time to the present," adds Spray. 

The APXS and other instruments will be used to help interpret this data.

Spray, Elliott and Thompson team up with NASA

Over the next two years, Spray and scientists at the Jet Propulsion Laboratory in Pasadena, California, will analyze the data and look for evidence of environments that could have supported life.

"The mission itself is to identify suitable habitats for life; so where life could have existed, such as lakes, rivers, and oceans."

Beginning of the expedition 

For Spray, the search for life on Mars actually began much closer to home. Having first studied geology in the United Kingdom, Spray later obtained his PhD in Earth Sciences at Cambridge University. Moving to Canada in 1987, he began working with impact craters.

"I started off working on terrestrial rocks, like most geologists, and it was only when I came to Canada 25 years ago that I started to work on impact craters," he says.

"In Europe, in the UK, there aren’t many impact craters, whereas in Canada they are numerous. We have the Canadian Shield and it is very old geologically, and the further you go back in time the more likely you are to encounter them."

Heavily cratered, Mars’ geology is very different than Earth’s. With relatively few craters on Earth, there are also few experts.

"We are one of the biggest groups in the world here (at UNB), so it is quite natural for us to be involved in planetary exploration missions, because most planets, unlike Earth, are heavily cratered," says Spray.

"Most geologists on Earth don’t know much about craters, but if you work on the moon, or with lunar rocks, or Martian rocks like we do, you are sought for that type of expertise. Both Beverley Elliott and Lucy Thompson trained at UNB as graduate students and that is how they are also involved - because of their planetary expertise."

Working in Martian time

As they begin examining the data being beamed back to Earth from Mars, Spray and his colleagues at the Jet Propulsion Laboratory will be working in Martian time, quite literally.

"The three of us will be working 90 days, or 90 sols,” explains Spray. “A sol is a Martian day."

Because its rotation time is slightly different than Earth’s, Mars’ days are longer. This leads to complications. 

"For every day we work on this project we add about 37 minutes because that’s how much longer a Martian day is compared to ours,” adds Spray. “So you get completely out of sync with Earth time, which can be confusing."

The Curiosity rover is different than previous rovers in that it is powered by a nuclear generator, rather than by a solar energy source. This allows the Curiosity rover to operate 24 hours a day, seven days a week.

"This will also allow it to travel very long distances, and it will probably operate for a decade, or maybe two," estimates Spray.

The Curiosity rover is also built to withstand wind, dust, and drops in temperature. Getting stuck on top of the mound is the only real issue to worry about, says Spray. 

As a proud UNB researcher and faculty member, Sprays believes that the Curiosity project is great opportunity to showcase smaller universities’ capacity to do big research.

"I think it is important for UNB in the sense that it shows we are not only a teaching university, which is a great thing in itself, but also that we do research at the international level, and work with JPL and other institutes," says Spray.

"You don’t necessarily have to be at the University of Toronto, or McGill or UBC to do good research. You can be at smaller universities like UNB which, quite frankly, punches above its weight in terms of cutting-edge research."

Contributed by Bronté James, Communications and Marketing. Story made possible through UNB Associated Alumni.