Talk like a planetary geologist

Canadian Space Agency (CSA) — the national space agency for Canada

Extravehicular activity — a spacewalk or any other activity performed by an astronaut outside a spacecraft while in space

Impact cratering — the formation of craters on a planet or moon’s surface due to the collision of asteroids or comets

Lunar regolith — the layer of loose, fragmented rock and dust that covers the surface of the Moon

The National Aeronautics and Space Administration (NASA) — the US agency for American aeronautics and space research

Polar desert — a dry, cold environment with little precipitation (such as rain or snow) and vegetation, similar to conditions found on Mars

Solar system volatiles — substances like water, carbon dioxide and methane that can exist as gases or ices in space and that play a role in planetary formation and habitability

When we think of space exploration, we often picture rockets launching into space, astronauts floating in zero gravity and robotic rovers exploring distant planets. But before we can fully understand places like Mars and the Moon, we need to study environments much closer to home. Certain locations on Earth share striking similarities with these distant worlds, allowing scientists to test technology, train astronauts and learn more about planetary history.

One such place is the Arctic – a vast, remote region with extreme cold, barren landscapes and ancient impact craters. These conditions make it an ideal natural laboratory for planetary research. Dr Gordon (Oz) Osinski, a planetary geologist at Western University, investigates impact craters and icy landscapes to advance our understanding of Mars and the Moon. He also plays a key role in astronaut training and is involved in several upcoming international space missions.

How is the Arctic similar to Mars and the Moon?

As a polar desert without vegetation, the Arctic is one of the best places on Earth to study landscapes that resemble those on Mars and the Moon. “In terms of geology, large parts of the Arctic are excellent analogues for Mars as they are shaped by processes involving ice,” explains Oz. “We see landforms such as patterned ground and gullies that we also see in the mid-to-high latitudes of Mars, so by studying the landforms on Earth, we can better understand processes on Mars.”

A particularly significant site is the Haughton impact structure, a 23 km-wide meteorite impact crater in the Canadian Arctic. As one of the best-preserved impact craters on Earth, it provides a rare opportunity to study impact cratering – a process that has shaped the surfaces of Mars and the Moon for billions of years.

How do astronauts learn geology?

“Almost none of the astronauts I have trained so far have ever studied geology before, so the first aspect is teaching them the fundamentals of geology, such as the main types of rocks and major processes that shape our planet and other planetary bodies in the Solar System,” says Oz. “We then focus on teaching observational skills and how to conduct field geology: what types of data we want them to document, what they should look out for, etc.” For upcoming missions like NASA’s Artemis III, which aims to explore the Moon’s surface in great detail, scientists need astronauts to be able to collect geological samples accurately. This includes understanding which types of rocks and minerals are most valuable for study and ensuring they can document each sample’s context to maximise its scientific potential once back on Earth.

What will Canada’s first lunar rover explore?

The Canadian Space Agency’s first lunar rover mission is set to explore the south pole of the Moon, a region that has become a primary focus for lunar exploration. One of the most exciting aspects of this area is the presence of permanently shadowed regions, which are areas that never receive sunlight and are thought to contain water ice (ice formed by water, as opposed to other liquids). “The rover has three main objectives: studying the lunar polar geology and the mineral resources in this area, investigating the cold traps where the water ice might be stored, and carrying out environmental monitoring to ensure the safety and health of astronauts in the future,” explains Oz.

The rover is expected to launch no earlier than 2026 as part of Canada’s ongoing efforts to contribute to space exploration.

What role is Oz playing in NASA’s Artemis III mission?

Dr Osinski is part of the geology team for NASA’s Artemis III mission, which aims to return astronauts to the Moon’s surface for the first time in over 50 years. The geology team’s primary responsibilities are to define the mission’s scientific objectives, evaluate potential landing sites on the Moon and plan the geology tasks that astronauts will carry out during their extravehicular activities – that is, their spacewalks. “With the team, I am the co-lead for one of the four science goals: impact cratering,” says Oz. “I am also part of a subset of the team that will be the first to study the samples that will be collected and brought back to Earth by the astronauts.”

Artemis III will focus on understanding the Moon’s early evolution, the impact history of the inner solar system and the Moon’s regolith (the loose, fragmented material covering the surface). The mission will also explore the age and origin of solar system volatiles – materials like water and gases that play a critical role in supporting life. Preparing for such scientific objectives involves extensive training to ensure that the team is fully ready for operations on the lunar surface.

The ExoMars 2028 Rosalind Franklin rover mission

Oz is also contributing to the European Space Agency’s ExoMars 2028 Rosalind Franklin rover mission, as a co-investigator on the PanCam camera and the Enfys instrument – highly specialised equipment that will work together to identify minerals when the rover lands on Mars.

Oz’s contribution to these three major projects highlights the truly international, collaborative nature of his work as a planetary geologist.

What are the challenges of such missions?

One of the challenges Oz faces with Artemis III is becoming an expert in a lunar region he is less familiar with up to now. “While I have studied the Moon before, I am having to become an expert in the geology of the south polar region, which is where this mission will land,” he says. “Impact cratering – which is my expertise – is just one of the four science goals, and so I am enjoying learning more about the other science goals too.”

For ExoMars, the biggest hurdle has been the delays caused by the Russian invasion of Ukraine, which has pushed the mission back several years. Nevertheless, the team remains committed to advancing our understanding of other planets and is excited about the potential discoveries ahead.

As planetary geologists like Oz know, overcoming such challenges results in exciting scientific discoveries – both on Earth and in space.

Dr Gordon Osinski
Earth and Planetary Materials Analysis Laboratory, Department of Earth Sciences, Western University, Ontario, Canada

Fields of research: Planetary geology, astrobiology

Research project: Investigating Arctic geology to advance our understanding of Mars and the Moon

Funders: Natural Sciences and Engineering Research Council of Canada (NSERC), Canadian Space Agency (CSA)

Website: spacerocks.ca

About planetary geology

Planetary geology is the study of the geology of planets, moons and other celestial bodies in our Solar System and beyond. The field examines the physical features, history and processes that shape planets and other objects, from surface features like craters and volcanoes to the internal composition and tectonic activity beneath. Planetary geologists use a combination of fieldwork, satellite data and samples from other worlds to better understand the evolution of our Solar System.

Planetary geology requires an interdisciplinary approach, drawing on knowledge from chemistry, physics, biology and computer science. The field is constantly evolving, especially with ongoing missions to Mars and the Moon. “This is an exciting time to be a planetary geologist, perhaps the most exciting in history,” says Oz. “We have robotic spacecraft continuing to explore the solar system and the prospect of humans returning to the surface of the Moon with the Artemis III mission. This mission will bring back many kilograms of samples that scientists will study for years to come.”