Dinosaur Provincial Park received a special pair of visitors in August: Drs. Pan Conrad and Dina Bower of the Planetary Environments Laboratory at the NASA Goddard Space Flight Center in Maryland. Dr. Conrad is an astrobiologist and mineralogist. She studies both minerals and extraterrestrial life. Dr. Bower is a palaeobiologist and geobiologist—she studies microbes from the beginning of life on Earth. Both are involved in the search for proof of prehistoric life on Mars.
Mars and Earth formed at the same time but look radically different now. It’s unclear if this is merely because of their respective locations (Earth is in a sweet spot, Mars not so much) or because Mars was damaged in some way. About four million years after the planets were formed, asteroids shot through the solar system and Mars may have been hit so badly that the planet re-melted. We do know that its magnetic field was lost, which means the planet has no protection against deadly radiation, both background radiation and from the sun.
Why does this matter? These deadly radioactive particles are able to strip away a planet’s atmosphere. It’s possible that life emerged at the same time on both Earth and Mars (either concurrently or one seeded the other—yes, there is a possibility that all life on Earth is technically extraterrestrial); however, life on Mars was thwarted. While there are no signs of life on the surface of Mars, there may be evidence beneath the surface. As there are a lot of rocks on Mars, the challenge is figuring out which ones may hold the fossils of early life.
We know roughly when life emerged on Earth, so the best place to start looking is in rocks that are the same age, but dating rocks on Mars is tricky. On Earth, we need to know the mass of a sample in order to accurately date it. As there is currently no way to bring samples back from Mars, how can we get samples to analyze?
That’s where Dr. Conrad and Dr. Bower come in. They have developed a technique to date rocks without needing to know their weight. The instrument they built, which uses potassium-argon dating, can be sent to Mars to date the rocks on site.
How does it work? To get to the old rocks on Mars, they need to be able to sample lots of layers, so a robot rover would rappel down a cliff with a small drill, taking samples from different stratigraphic layers. It would then powder these samples and deliver them to the dating instrument that will provide data on the age of each of the rock layers.
Problem solved! Or is it? Before it gets put on a rocket, the instrument and rover need to be tested to make sure they work as they are supposed to. As Mars is a completely different environment, the researchers needed to find a test site that would closely match Mars as closely as possible. The answer was Dinosaur Provincial Park.
In order to do their tests, they needed an expert in Alberta geology. Dr. David Eberth, Senior Researcher, Sedimentary Geology at the Royal Tyrrell Museum was able to help. As an expert on Alberta’s Cretaceous rocks, especially those used for dating, Dr. Eberth agreed to tour the pair through the Park so they could begin the next phase of their project.
This initial visit had two objectives: to test the accuracy of the dating instrument and do a survey of the landscape for possible testing of the rover. The rocks in the Park include beds of bentonite—ancient altered volcanic ash that has been dated and studied by Dr. Eberth and his colleagues. By comparing the dates their instrument will get with those obtained by Dr. Eberth, Drs. Conrad and Bower can test the functionality and accuracy of their tools and methods. If the results match Eberth’s, they will know that the instrument is one step closer to going to Mars.
Even after testing the dating instrument, they have to make sure that the rover is able to rappel down Martian cliffs to get the samples to date. Before they send a multi-million dollar piece of equipment into space, the researchers have to know that it is not going to fail the first time it tries to go over a cliff. Therefore, a large portion of the day was spent surveying different areas of the Park to get a sense whether it might serve as a stand-in for Mars.
The first site Dr. Eberth took them to had bentonite that was clean and uncontaminated, although the crystal content was a little lacking. The presence of macroscopic crystals (crystals that can be seen with the naked eye, as opposed to microscopic crystals) are a good indicator of high mineral content, which is easier to date. Despite the low number of crystals, it was still a nice sample. It was not, however, a good spot to test the rover. There were many micro-buttes on the cliff that the rover’s tether could snag on.
At a second site, the bentonite was too contaminated to date. It was full of clintonites, a kind of mica, giving it a dusky appearance. Healthy bentonite should have a green, waxy look.
The researchers took only one more sample, in an area inaccessible to tourists. While they didn’t find a location that made them shout “Yes, this is exactly like Mars!” they did get an excellent sense of the landscape and the forces that shaped it. This will allow them to accurately plan a mission scenario.
The day ended on a jubilant note. With the data collected, the scientists can move on to the next phase of their project, testing the apparatus and making plans for future work. While there were some disappointments searching for viable sites, it was a solid start on a project that will hopefully end in proving the existence of life on Mars.
And it turns out that even alien hunters are not immune to the wonder of dinosaurs.