Keith's 30 Nov note: As has happened before, NASA puts out advance notice of a provocative major discovery, media advisory and speculation goes into overdrive with titles of articles such as "Has NASA found life near Saturn?" based on a single, speculative blogger post.
Calm down folks. According to Alexis Madrial, a senior editor at The Atantic (and used to write for Wired) posting on Twitter "I'm sad to quell some of the @kottke-induced excitement about possible extraterrestrial life. I've seen the Science paper. It's not that." followed by "I'm obviously not the only one. It's available to journalists with access to embargoed EurekAlert content."
An article by several of the individuals (Benner, Wolfe-Simon) who will be participating in the telecon can be found below. Is NASA's announcement related to NASA's announcement? Who knows.
Signatures of a Shadow Biosphere, Astrobiology, Volume 9, Number 2, 2009 via The Smithsonian/NASA Astrophysics Data System (A copy of the full article can be found here.) Authors: Paul C.W. Davies, Steven A. Benner, Carol E. Cleland, Charles H. Lineweaver, Christopher P. McKay, and Felisa Wolfe-Simon
"Astrobiologists are aware that extraterrestrial life might differ from known life, and considerable thought has been given to possible signatures associated with weird forms of life on other planets. So far, however, very little attention has been paid to the possibility that our own planet might also host communities of weird life. If life arises readily in Earth-like conditions, as many astrobiologists contend, then it may well have formed many times on Earth itself, which raises the question whether one or more shadow biospheres have existed in the past or still exist today. In this paper, we discuss possible signatures of weird life and outline some simple strategies for seeking evidence of a shadow biosphere."
Then there is this article by another one of the authors (Wolfe-Simon) dealing with putative life forms that use Arsenic instead of Phosphorus in their biochemistry. Again, the concept of a "shadow biosphere" and thoughts as to whether this can be applied to extraterrestrial locations are discussed.
Did nature also choose arsenic?, International Journal of Astrobiology, Volume 8, Issue 2 via via The Smithsonian/NASA Astrophysics Data System
"All known life requires phosphorus (P) in the form of inorganic phosphate (PO43- or Pi) and phosphate-containing organic molecules. Piserves as the backbone of the nucleic acids that constitute genetic material and as the major repository of chemical energy for metabolism in polyphosphate bonds. Arsenic (As) lies directly below P on the periodic table and so the two elements share many chemical properties, although their chemistries are sufficiently dissimilar that As cannot directly replace P in modern biochemistry. Arsenic is toxic because As and P are similar enough that organisms attempt this substitution. We hypothesize that ancient biochemical systems, analogous to but distinct from those known today, could have utilized arsenate in the equivalent biological role as phosphate. Organisms utilizing such 'weird life' biochemical pathways may have supported a 'shadow biosphere' at the time of the origin and early evolution of life on Earth or on other planets. Such organisms may even persist on Earth today, undetected, in unusual niches."
Are these articles related to NASA's announcement? Reliable sources within the Astrobiology community tell me that the announcement does indeed concern Arsenic-based biochemistry and the implications for the origin of life on Earth, how it may have happened more than once on our planet, and the implications for life arising elsewhere in the universe.
Close Encounters of the Media Kind, Columbia Journalism Review
"Posts at MSNBC.com's Cosmic Log blog, Discover's Bad Astronomy blog, and at the independent NASA Watch blog also tried to quell the otherworldly hysteria. (Further efforts have since appeared at the Associated Press and Time.) ... "This shows how important an experienced, trained and authoritative science journalism staff of reporters and editors is," AP science reporter Seth Borenstein wrote in an e-mail, responding to questions about the blog frenzy. "While the blogosphere has the luxury of speculating, The Associated Press seeks to be the definitive source through careful reporting and knowledge of the subject area."