Spray, Elliott and
Thompson team up with NASA

Following a tense and delicate – yet ultimately successful –
landing on Mars last August 6, NASA’s Curiosity rover almost immediately began sending
information back to Earth. On that early Monday morning, John Spray was at the
Jet Propulsion Laboratory in California, one of numerous scientists unable to
contain his excitement.

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

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.

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

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

“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.