Exploration geologists and astrobiologists share a keen interest in sampling and analyzing rocks for their metallic content, but while geologists are looking for the next big discovery of base and precious metals, astrobiologists are hoping to learn about the origin of life.
Fifty-five astrobiologists from around the world converged on Sudbury in September to pursue their quest on field trips in the Sudbury Basin and across Northern Ontario.
Convened under the auspices of NASA’s Astrobiology Institute, the event offered scientists and graduate students from Canada, the U.S., Australia, Japan and Europe an opportunity to look for biosignatures of early life in Northern Ontario rocks.
Biosignatures of early life “are a combination of chemical characteristics in a rock that could not arise in any other fashion than by life,” explained Dr. Balz Kamber, Canada Research Chair in Precambrian Geology at Laurentian University.
“Typically, you would be looking for a fossil, but the majority of life forms never get fossilized. When you find a good fossil, you’re lucky. And, if you’re looking at relatively simple life forms such as bacteria or viruses, your chances of finding a fossil are essentially zero.”
Fortunately, bacteria, viruses and other simple life forms do “leave behind chemical signatures of their former existence,” said Kamber.
The Astrobiology Institute was established by NASA in 1998 “to study the origin, evolution, distribution, and future of life on Earth and in the Universe.”
The 1996 discovery in Antarctica of a meteorite from Mars containing potential biosignatures of early life led NASA to support further research that could assist in unraveling one of the biggest mysteries in the universe.
Scientists were unable to agree on whether the suspected biosignatures provided evidence of life on Mars, “but it was recognized that we need to come up with a consensus about what is a valid biosignature,” said Kamber.
“That’s what led to the establishment of the Astrobiology Institute.”
Consensus
The workshop in Sudbury “didn’t come up with a definitive set of what the majority of researchers would agree to be biosignatures, but what the workshop did come up with is a catalogue of possible biosignatures that now need to be tested for their uniqueness.”
NASA’s hope is that by advancing our understanding of the search for the origins of life on Earth, we will be able to determine if life once existed on Mars and other planets.
Sudbury is of interest to astrobiologists because of the meteorite that created the Sudbury impact crater 1.85 billion years ago.
Most scientists believe that life originated on Earth 3.8 billion years ago, shortly after a period of heavy meteor bombardment,” explained Kamber.
“If we want to understand how life might have originated on Earth, we need to understand what sort of environment these craters could have offered for life to spring up, and the best preserved, large impact structure on Earth is the Sudbury Basin.
“The impact itself would have wiped out any pre-existing life around Sudbury. But life would have come back and recolonized the crater structure.”
Understanding how life sprung up again after the impact could shed light on how life originated on Earth, said Kamber.
Fortunately, the Sudbury Basin has been squeezed and tilted by subsequent geological activity, so it isn’t necessary to go underground to see the sequence of rocks from various points in time. They are all on display in rock cuts along Highway 144 connecting Sudbury and Timmins
The search for the origin of life may be a bit esoteric for the mineral exploration industry, but it is benefiting all the same from the funds that are being invested to analyze trace elements at parts per billion concentrations, said Kamber.
“We could not imagine that we would ever be able to analyze elements at such low concentrations. It would have been prohibitively expensive to buy the equipment, train the people and do all the testing and analysis, yet the Astrobiology Institute will pump money into such laboratories.”
A mass spectrometer at Laurentian University’s Earth Sciences laboratory was funded by the Canada Foundation for Innovation as a result of Kamber’s proposal for a Canada Research Chair and his interest in astrobiology.
The Laurentian lab has done work for De Beers and for mining companies in Australia, but the facility is still underutilized, said Kamber.
“Every orebody has a halo, a zone from which the ore was mobilized and the farther out you can see into that halo, the earlier you can sniff the orebody.
“Many of the metals that are of interest to astrobiologists are also of interest to the exploration industry.
Molybdenum is one of them. Most laboratories nowadays can’t analyze molybdenum because it’s normally present in very low concentrations. Cadmium is another one, but we can offer this analysis. We can see molybdenum and cadmium at very low concentrations.”
www.chemicalfingerprinting.laurentian.ca
http://nai.nasa.gov
