By training, I’m an astronomer. Growing up and all through my university years, my mind was always in the stars. As a journalist, however, I’ve found myself learning things about geology I never learned in school. At my first planetary science conference back in 2003, I found out that here on Earth, we have volcanoes that are in every scientific way the same as volcanoes on Mars and the Moon, and researchers will study satellite images of all the different worlds looking for the things that look the same from space, so they can hike out with tools and literally poke and hammer on the versions here on Earth. 

The Earth features that are like geological features on other worlds are called analogs, and they come in many forms. There are sub-freezing, volcanic caves here on Earth that are like those on Mars, we think, and dune fields migrating across the Australian desert that are like the dunes on every terrestrial world with an atmosphere.

Studying these Earth analogs to features on other worlds is particularly important as we prepare to send rovers, fliers, and even people to other worlds. The Dragonfly mission to Saturn’s moon Titan will take off in 2027 with plans to land near a large crater in 2036. This site was selected because the energy of an impact would melt the icy surface of Titan and possibly allow for the kinds of chemical reactions that could lead to life to begin to take place. Because everything would re-freeze, it’s expected these chemical reactions got stopped partway through whatever they were doing, and Dragonfly is going to flit around trying to understand how close to supporting life Titan got.

To most effectively use the little flier, researchers need to understand where in the crater’s structure what kinds of things may have occurred. This means looking for an Earth analog.

Titan has such a cold temperature and sufficiently low gravity that in its thick atmosphere, methane acts like water does on Earth. It rains and snows and freezes and flows in streams, all according to the seasons. To find a Titan-like crater on Earth meant looking for a crater in the permafrost.

And Canada was happy to oblige. The Haughton Impact Structure on Devon Island in northern Canada formed about 23 million years ago. While flowing water and moving glaciers have worn away some of the impact structures, its central region still has pristine materials formed during the impact, and remarkably, some of these materials are exposed thanks to those rivers and other forms of erosion. According to a presentation at a conference yesterday that was given by Catherine Neish on behalf of her team, sampling Haughton allows them to experimentally confirm where organic molecules concentrate and where cliff faces erode and dump their material.

I look forward to seeing researchers explore this crater with their drones and good old-fashioned hiking gear, as we learn what Dragonfly may find on Titan and practice for its explorations.

More Information

PDF: The Haughton Impact Structure as a Titan Impact Crater Analogue: Applications to the Dragonfly Mission (conference abstract)