Geologists examining a breccia hill.

Mars today is mostly a cold, windy, barren, rocky desert, with many ancient impact craters, channels, valleys, canyons, possibly ancient lakebeds, and many other features. No place on Earth is truly like Mars: on Mars gravity is weaker, the atmosphere is thinner, drier and made of carbon dioxide (CO2), radiation from space is more intense, temperatures can be much colder. But the polar regions on Earth come close in some respects. On Devon Island in the Canadian High Arctic, there is a unique combination of circumstances: an ancient impact crater (Haughton Crater) set in a cold, windy, barren rocky desert, with nearby channels, valleys and canyons that bear a strong resemblance to many of the channels, valleys and canyons seen on Mars. What then can we learn about Mars by studying Haughton and Devon? What can we learn about how to explore Mars with robots and humans? To answer these questions, the NASA Haughton-Mars Project began studies in 1997 and has visited the site every year since. Devon is turning out to be a Mars analog wonderland and is the site chosen by the Mars Society to establish its Flashline Mars Arctic Research Station.

Aerial view of Haughton Crater

Haughton Crater is 20 km in diameter and formed 23 million years ago (Miocene). The exact size and speed of the impactor are unknown, but it may have been 0.5 mile across and travelled at several tens of kilometers per second. At the time of the impact the Earth was warm and Devon had a climate somewhat like that of Toronto today. There were trees (conifers, leaf-bearing trees) and many animals (a little Rhinoceros, rabbits, fish). In an instant, all life at the site was wiped out. From a biological standpoint, the impact was a resetting event on at least a regional scale, and biological studies at Haughton are very important, even if there were no Mars connection. The rocks that were impacted (mostly ancient marine sediments over 300 million years old, replete with fossils, some of primitive corals and stromatolites) were in part vaporized or crushed and ejected from the crater. Even basement rocks from about a mile deep were excavated and launched into the sky. As the ejected rocks rained back down, heaps of impact rubble accumulated to form the beautiful Haughton impact breccia, still well preserved today.

A polar bear taking at a stroll at the periphery of Haughton Crater.

The Haughton breccia is now permeated with ground-ice and may provide the closest natural analog to the martian regolith (the surface rubble on Mars generated by impacts). By studying the breccia, we might for instance learn about the possible distribution of subsurface ice on Mars. After the impact, temporary hydrothermal vents became active in and around the crater. They provided isolated sites of enhanced moisture and warmth and are therefore of great biological interest. Might similar impact-induced ancient hydrothermal vents be found on Mars? Water also collected inside Haughton crater and lake sediments were deposited. The lake waters eventually drained away but the ancient lakebeds can still be found. By studying these lakebeds, we can learn how to recognize possible counterparts on Mars, sample them and study them for their climatic and fossil record. There are also the many channel networks, valleys and canyons outside Haughton Crater. Most of these were formed in direct connection with past glaciations, either by direct glacial carving or by the melting of glacial ice. If the valley networks and canyons on Mars were formed in a similar way, then there might be no reason anymore to invoke a warm climate on Mars in its past. Our studies on Devon are opening the alternative perspective that Mars may have always been climatically cold, albeit wet at times, not "warm and wet". What would that mean for its prospects for harboring life? At Haughton, microbial life proves to be very adaptable and can be found almost everywhere - inside rocks, at the bottom of ponds. Even if Mars was always cold, its propsects for having possibly evolved life remain very good.

In all our wanderings on Devon we are also learning how to explore Mars with humans. We test communication systems with imposed time delays for links with Mission Control, we try out new robotic technologies, new spacesuits, we study human factors and a variety of other exploration technologies and strategies that are essential to understanding how a human mission to Mars can be successfully carried out. The Flashline Mars Arctic Research Station will serve in this context as a very valuable operational testbed, a realistic framework for constraining how humans will have to live and work on Mars to be effective explorers. Our work on Devon will represent an important step in the direction of getting humans to Mars.