“NASA will hold a news conference at 2 p.m. EST on Thursday, Dec. 2, to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life.”
Think about that for a minute.
Have they found a secret Martian base?
From the background of the participants it sounds more like they have found some extra-terrestrial basis for life that is different from most life here on Earth. I would guess that it is arsenic-based biochemistry happening on Titan.
Let’s look at the participants:
Mary Voytek, Director, NASA Astrobiology Program
“Dr. Voytek’s primary research interest is aquatic microbial ecology and biogeochemistry. She studies environmental controls on microbial transformations of nutrients, xenobiotics, and metals in freshwater and marine systems.”
Felisa Wolfe-Simon, NASA astrobiology research fellow
“I apply a background in molecular biology, biochemistry, and phytoplankton physiology to uncover the sequence of events that shaped the evolution of the modern oceans phytoplankton and life itself.”
“Arsenic as a prebiotic chemical analog of phosphate ( Wolfe-Simon, Davies, & Anbar, 2009). Essentially, arsenic (in the oxidized 5+ state as arsenate) is biologically, so similar to phosphate that many enzymes cannot recognize the difference. This constitutes the basis for much of the toxicity of arsenate and so most detoxification pathways in biology aim to reduce arsenate to more volatile forms for easier removal from biological systems. However, due to the increased mobility of reduced arsenic species, often the toxicity of arsenic increases as the redox state decreases.
To further this hypothesis, we have embarked on two different approaches to test assimilatory arsenic utilization. Firstly, as part of the NASA Astrobiology Institute we are examining arsenate-rich environments to hunt and enrich cultures for organisms utilizing arsenate in novel and unique modes.Here is a good recent review on what is known about arsenic microbial pathways put in an astrobiological context (Oremland, Saltikov, Wolfe-Simon & Stolz, 2009).
In concert with this in situ and/or in vivo type work, we are also collaborating with Dr. Steve Benner and Dr. Nicole Leal at The Foundation for Applied Molecular Evolution and Dr. Marcelo Guzman to measure the spontanous incorporation of arsenate into a DNA backbone.
There are other approaches to search for life “as we do not know it” here on Earth. For more information, check out this paper (Davies, Benner, Cleland, Lineweaver, McKay & Wolfe-Simon, 2009).”
Pamela Conrad, astrobiologist, NASA’s Goddard Space Flight Center
Pamela was a primary author of Geochronology and Mars Exploration which focuses on the planetary process as a foundation for framing geological and biological evolution.
Steven Benner, distinguished fellow, Foundation for Applied Molecular Evolution, Gainesville, Fla.
“While ‘life’ may universally be a self-sustaining chemical system capable of Darwinian evolution, alien life may be quite different in its chemistry from the terrain life that we know here on Earth. In this case it will be difficult to recognize, especially if it has not advanced beyond the single cell life forms that have dominated much of terran biosphere.” [Chemistry, Life, and the Search for Aliens]
Benner is on the Titan team at Jet Propulsion Laboratory. He was an early proponent that the methane on Titan could play the role that water plays for life here on Earth.
James Elser, professor, Arizona State University
Is a champion of the “follow the elements” in addition to water when searching for extra-terrestrial life.
Titan is the largest moon of Saturn, with a dense atmosphere and bodies of liquid on its surface. It’s about 50% larger in diameter than Earth’s moon and bigger than the planet Mercury.
The Cassini–Huygens mission in 2004 discovered liquid hydrocarbon lakes in Titan’s polar regions. These are the first stable bodies of surface liquid found off Earth.
See also
