Mars Once Had Salty Oceans – Just Like Earth.
On the same day that NASA was announcing the apparent presence of liquid water near the surface of Mars, another research team announced that Mars once had salty oceans like those we have on Earth. A world once thought to be dried out and dead is becoming more “Earth-like” every day.
According to a press release from the University of Arizona, “a recent analysis of the interior of a 1.2 billion-year-old Martian meteorite known as the Nakhla meteorite has shown the presence of water-soluble ions that are thought to
have been deposited in cracks by evaporating brine.” The finding, according to the release, “indicates that ancient Martian oceans had a chemical composition similar in variety and concentration to Earth oceans. “
The researchers arrived at this conclusion by studying the amount of chlorine and sulfur in samples of basalts from all over the solar system. The meteorites that were comparatively high in chlorine were pieces of Mars whereas those with low levels of chlorine were pieces of asteroids. According ASU’s Carleton
Moore further analysis of a piece of the Nakla meteorite showed that “the highest concentrations of negative ions were chloride, sulfate, fluoride, and a little dissolved silica, and, in positive ions, sodium, magnesium and calcium. The elements in highest abundance were sodium and chloride — like the salt water on Earth. In ocean water, these are the predominant ionic elements. We are interpreting the elements that we have extracted as having come from an early Martian ocean.”
The Nakhla meteorite is so named for having fallen amidst a shower of rocks on 28 June 1911 near the Egyptian town of Nakhla. Local lore has it that one of the meteorites killed a dog. Years later, comparisons made between these meteorites and data returned from the Viking lander provided clear evidence that this meteorite (and others) were actually pieces of the planet Mars.
Only 13 known examples of Martian meteorites are known. The 13th, from Oman, having been identified earlier this year. ALH84001, the meteorite within which putative Martian fossils were found in 1996, is another piece of Mars.
While the announcements made regarding ALH84001 in 1996 garnered much more attention, the same NASA JSC research team that made the ALH84001 discoveries suggested in a somehwat less publicized 1999 paper that the Nakhla meteorite also shows evidence of Martian bacterial fossils.
The past several weeks have seen the announcement of four discoveries with strong implications for Astrobiology. Each discovery is significant in it own right. When taken together, however, they outline a rather profound prospect: that the universe – both nearby and far away – seems to be littered with the life’s basic components.
Two weeks ago astrochemists announced that they had found salt crystals containing brine water inside the “Zag” meteorite. The crystals formed within 2 million years of the birth of our solar system. This discovery would seem to suggest that the conditions (or at least the prime ingredients) required for the origin of life may have existed at a very early period of solar system formation.
A week later radio astronomers announced that they had detected the sugar glycolaldehyde in Sagittarius B2 (North), a gas and dust cloud 26,000 light years away near the center of our galaxy. Glycolaldehyde, a simple sugar, can combine with other molecules to form the more complex sugars Ribose and Glucose. Ribose is a building block of nucleic acids such as RNA and DNA.
Last week NASA’s Mars Global Surveyor team announced that they had discovered compelling evidence that liquid water has affected the surface of Mars and that these processes may still be active today. Given that Mars has the basic chemical components need for life, and abundant energy sources, this discovery provides the “smoking gun” (according to the University of Colorado’s Bruce Jakosky) regarding Mars’ ability to have supported life at some point.
In December 1999, Mars Global Surveyor scientists announced that topographical measurements made of the surface of Mars using the Mars Orbiter Laser Altimeter are consistent with an ocean that dried up hundreds of millions of years ago. On the same day, an announcement was made by a nother research team that living bacteria had been found in a fresh water lake located 2 miles beneath the surface of the Antarctic ice cap – a lake that had remained utterly dark and isolated for millions of years.
It seems that not a week goes by without an announcement of yet another discovery which shows either that the building blocks of life are abundant throughout the universe; that life on Earth (and presumably life elsewhere) can survive in very harsh environments; that more (and smaller) planets orbit other stars; or that other worlds in our solar system (Mars and Europa) seem to have many or all of the components and conditions required to support life.
Related Links
° Meteorite research indicates Mars had Earth-like oceans, Arizona State University
° Water soluble ions in the Nakhla martian meteorite, Journal of Meteoritics & Planetary Science 35 (July 2000)
° The Nakhla Meteorite, NASA JPL
° Nakla Meteorite (Adobe Acrobat), Mars Meteorite Compendium
Background Information
° Journal of Meteoritics and Planetary Science
° Mars Meteorite home page, NASA JPL
° Meteorites from Mars, NASA JSC
° Possible Bacteria in Nakhla, 30th Lunar and Planetary Science Conference (Adobe Acrobat)
° It’s dead Jim. But was it ever alive? The ALH84001 announcement at T+2 years, Ad Astra
° New Mars Meteorite Found In Oman (May 2000), NASA JPL
° Liquid Water on Mars: The Story from Meteorites, Hawai’i Institute of Geophysics and Planetology
° Astronomers Find Sugar Molecules In a Dust Cloud at Our Galaxy’s Center
° Meteorite Found to Contain Water From Our Solar System’s Infancy
° Mars Global Surveyor Provides Evidence of Ancient Martian Oceans, SpaceRef
° Brown geologist finds evidence supporting ancient ocean on Mars, press release
° Life Found Deep in Antarctica’s Lake Vostok: Implications for Life on Other Planets
