Scientists have found that 200 meteorites found on Earth can be traced back to just five impact craters on Mars. These Martian relics offer invaluable insights into the red planet’s ancient volcanic activity and geological history.
MARS’ VIOLENT PAST: METEORITES EJECTED INTO SPACE
Powerful impacts on Mars occasionally hurl debris into space with enough force to escape the planet’s gravity. Some of this ejected material finds its way into orbit around the Sun and eventually crosses paths with Earth, landing as meteorites. A team of researchers from the University of Alberta has pinpointed the origins of these space-travelling rocks.
FROM MARS TO EARTH: TRACING THE COSMIC JOURNEY
The study identifies that most Martian meteorites come from five impact craters located in two volcanic regions on Mars: Tharsis and Elysium. Chris Herd, curator of the University of Alberta’s Meteorite Collection, explains that when Mars’ surface is struck with sufficient force, material is blasted off and accelerated out of Mars’ gravitational pull. This process leaves behind impact craters on Mars and sends debris towards Earth.
MAPPING MARS’ METEORITE SOURCES
The research team has successfully mapped half of the sources of Martian meteorites, revealing that these rocks originated from specific craters created by past impacts. By understanding the physics of how these rocks are ejected, scientists can better estimate the crater sizes responsible for these meteorites.
REVEALING MARS’ GEOLOGICAL SECRETS
Herd notes that this breakthrough allows scientists to group meteorites by their history and origin on Mars. This improved understanding provides crucial context for interpreting the Martian samples on Earth. It also offers a chance to recalibrate Mars’ geological timeline, shedding light on the planet’s significant events.
THE MISSING LINK: EJECTION PROCESS MODELING
One major advancement from this study is the ability to model the ejection process of Martian meteorites. Herd describes this as the “missing link,” allowing scientists to determine the size of craters that could have ejected specific meteorites. For instance, impacts creating craters between 10 and 30 kilometres wide might explain the ejection of certain meteorites.
FUTURE DISCOVERIES: TARGETING UNTAPPED CRATERS
With the new framework established, researchers are now poised to explore additional Martian craters that have yet to yield meteorites. Herd highlights the potential to reconstruct volcanic stratigraphy—the geological layers of Mars—as if reading a book. This approach could reveal more about the planet’s past environments.
VERIFYING MARTIAN ORIGINS: THE FINGERPRINT OF MARS
To confirm that a meteorite is of Martian origin, scientists rely on a distinctive signature found within the rocks. Discovered in the 1980s, this “fingerprint” includes trapped gases that match the Martian atmosphere, as measured by Viking landers in the 1970s.
LOOKING AHEAD: NEW HORIZONS IN METEORITE RESEARCH
The study paves the way for future research, including targeted studies on meteorites ejected simultaneously. This approach promises to transform our understanding of Martian meteorites and the history of Mars itself. Herd expresses excitement about the potential for these advancements to revolutionize the study of extraterrestrial debris.
