Scientists are reporting that the molecular building blocks of life formed on Mars long ago. findings that suggest these molecules could form on any cold, rocky planet.
Organic molecules, containing carbon and hydrogen, are the major components of all Earthly life. In a new study, researchers with the Carnegie Institution in Washington, D.C. analyzed organic compounds in a Martian meteorite. Scientists had previously speculated that these might have landed on the red planet thanks to meteorite impacts there. The new study instead concluded that the materials probably formed on Mars itself, possibly as a result of volcanic eruptions.
The findings "show that volcanic activity in a freezing climate can produce organic compounds," said the institution’s Hans Amundsen, one of the researchers. "This implies that building blocks of life can form on cold rocky planets throughout the Universe."
The investigators compared the meteorite, called Allan Hills 84001, with rocks from Svalbard, Norway. These occur in volcanoes that erupted in a freezing Arctic climate about a million years ago, possibly mimicking conditions on early Mars, the scientists said.
"Organic material occurs within tiny spheres of carbonate minerals in both the Martian and Earth rocks," said Andrew Steele, lead author of the study. The scientists, he added, found the organic material in close association with a mineral called magnetite—"the key to understanding how these compounds formed."
When material blasted from Svalbard volcanoes cooled off, magnetite acted as a catalyst, or chemical instigator, for the formation of organic compounds from fluids rich in carbon dioxide and water, said the researchers. "The similar association of carbonate, magnetite and organic material in the Martian meteorite... is very compelling," they added in an announcement of their findings Tuesday. "This is the first study to show that Mars is capable of forming organic compounds at all." The study is published in the September issue of the research journal Meteoritic & Planetary Science.
Steele said the work "sets the stage for the Mars Science Laboratory mission in 2009"—a NASA rover designed to help assess whether Mars ever could, or can, support microbial life. One of its goals is to identify organic compounds and their sources, said Steele, who is part of the mission team. "We know that they are there. We just have to find them."
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