According to new research, organic molecules encased within meteorites from Mars reveal that these materials could not have been formed from biological activity on the Red Planet. On Earth, the compounds known as organic molecules can be linked to life.
Building blocks of life such as DNA and proteins are made from the carbon-based raw materials known as organic molecules. Such organic compounds have been discovered in Martian meteorites that crashed on Earth, but there has been a tough debate among scientists regarding their origin. On one hand, they might be signs of life on Mars, but on the other they may be just contaminants that reached the rocks after they landed.
11 Martian Meteorites Analyzed
In an effort to solve the mystery revolving around these organic molecules, researchers analyzed 11 meteorites from Mars, including the Tissint meteorite that fell into the Moroccan desert back in 2011. These rocks span 4.2 billion years of Martian history. The new research reveals that organic molecules encased within these meteorites did in fact originate on Mars.
"Mars apparently has had organic carbon chemistry for a long time," said Andrew Steele, study lead author and microbiologist at the Carnegie Institution of Washington, according to Space.com. While these organic molecules came from Mars, they do not seem biological in origin. "They formed from volcanic processes," Steele explained.
Complex Hydrocarbons
Ten of the 11 meteorites analyzed possessed complex hydrocarbons, i.e. compounds of carbon and hydrogen atoms. These complex hydrocarbons were found within grains of crystallized minerals that formed within cooling magma. "When the minerals crystallized from the magma, they trapped carbon in them, and over time, organic compounds formed within these mineral bottles," added Steele.
On Earth, tectonic processes shift matter around the planet, but Steele indicated the theory of such organic molecules from potential microbes on Mars making their way into the magma via geological activity is not plausible. "Such processes are very peculiar to Earth - Mars does not have tectonics."
Organic Chemistry
"We now find that Mars has organic chemistry, and on Earth, organic chemistry led to life, so what is the fate of this material on Mars, the raw material that the building blocks of life are put together from?" added Steele.
With this new study, scientists now have a better picture of the foundations of chemistry on Mars. They can now better look for anomalies that might indicate life during their missions to Mars. NASA's Mars Science Laboratory is scheduled to land the Curiosity rover on the Red Planet in August this year. "We'll see if there are hints that Mars is not a dead planet," said Steele. The new findings were published online on May 24 in the journal Science.
