Studies of the most recent Martian meteorite to touch down on Earth have once again sparked debates over the prospect of life on the Red Planet. Named Yamato oo593, this large chunk of Mars, found by a Japanese research expedition at the Yamato Glacier in Antarctica in 2000, shows evidence of distant water activity, but not only on Mars’ surface. They have found signs of past water having moved through the interior of Yamato. These findings have reopened debate about the feasibility of microbes in the ancient history of the Red Planet. Only these rocks from Mars can reveal these ancient secrets.
In the 1990’s, biogenic evidence was discovered in another meteorite named Allan Hills 84oo1, found in Allan Hills, Antarctica in 1984. This rock, weighing only 4.3 pounds, made a splash in newspapers when scientists proposed it could contain evidence of microscopic fossils of Martian bacteria, based on the presence of carbon globules. Possibly one of the oldest chunks of meteorite from the solar system, they believe it came from Mars, crystallized from molten rock four billion years ago. It is now on display under ALH84oo1 at the Smithsonian Museum of Natural History.
With the much larger, 30-pound Yamato meteorite, scientists have been able to examine its composition deep within the structure of the weighty rock. There, they have found the carbon-rich balls and tunnels that speak to the probability that Mars could have once teemed with primitive life. A team of scientists at NASA’s Johnson Space Center said that some of the structural features within the core of Yamato convey the probability that, “biological activity could have been happening on the Red Planet billions of years ago.” Based on chemical analyses, Yamato is believed to have originated on Mars from a period when flowing water, a requirement for the presence of life, was a part of the planet’s surface.
Although the Red Planet went through a wet period many billions of years ago and possibly nurtured life in microbial form, the current climate on the surface is extremely arid and below freezing. Mars does not have a dense atmosphere like earth, or an ozone layer, which would protect it from radiation from the sun and other elements in space. The effects of this kind of incessant radiation on any cellular surface would be completely damaging, which presents the main obstacle to the reality of any living organisms on Mars.
Scientists have been trying to ascertain whether there is, or has been, water on Mars in order to assess its potential for supporting life. Does the Red Planet have the resources necessary for the future of human exploration? In the first decade of the 21st century, NASA instigated a program to explore Mars and named their science theme, Follow the Water. There were many discoveries made by the Odyssey, the exploration rovers, the Reconnaissance orbiter, and the Pheonix lander. Each mission supplied invaluable information with answers to questions about the volume and dispersal of water on Mars. Based on evidence from the Curiosity rover as recent as December, 2013, which studied Aeolis Palus, the Gale Crater appeared to have contained an ancient fresh water lake, which might have been a life-friendly environment.
Innumerable lines of evidence would indicate that there has been an abundance of water on the surface of Mars, and that water has played a major role in the planet’s geological history. Today, any water, past or present, on Mars can be estimated from spacecraft imagery or remote sensing technology, as well as surface explorations by rovers and landers. These missions to Mars will always enlighten scientists on the striated face of the Red Planet, but according to a statement from the Jet Propulsion Laboratory, the single most informative way to glean any knowledge of the history of Mars or the possibility of the past existence of life is through the geology of the planet. Scientists will continue to study the meteorites as they are discovered, and although Mars will continue to baffle them, it is the rocks that will reveal the ancient secrets of the Red Planet.
By Christine Schlichte