Star Trek: Typhon Pact: Seize the Fire - By Michael A. Martin Page 0,10
from his position behind the tactical console. “I trust that I need not point out that proving a negative is a logical impossibility.”
Turning her chair halfway toward Tuvok, the exec nodded in agreement. “Isn’t absence of evidence sometimes just that? Absence of evidence?”
“As opposed to evidence of absence,” said the stellar cartographer. “Point taken. But biospheres always leave a mark on the worlds that host them. Even small, tenuous biospheres will make their presence known if your instruments are good enough. And our instruments are damned good.”
Riker considered the most tenuous native biosphere that existed in his own species’ backyard—that of Mars. The Martian ecology, marginal though it was by the time humans had developed any capability of studying it to any significant extent, had made itself known only by dint of the traces of atmospheric methane it released and maintained at slightly-above-equilibrium levels. Absent the continued action of a relative handful of hardy subsurface extremophile native microbe colonies, that methane would have quickly been photodissociated into its component elements and then dispersed or absorbed. And before Mars had been scrutinized under a sufficiently sensitive lens, those molecular traces had been undetectable; Mars, with its whisper-thin, oxygen-free atmosphere, had appeared already to be in an equilibrium state consistent with an eternally dead, lifeless desert.
“But as good as our instruments are,” Riker said, “couldn’t there still be an ancient biological marker that nobody’s been able to find yet—something so old it’s literally buried at the very bottom of the rock pile?”
“There’s a sharp limit to how old a fossil biosphere like that could be, Captain, given the atmosphere we’ve observed here. Class-M atmospheres are inherently out of equilibrium with the surrounding environment. Without biota to maintain them, they always deteriorate into something much less friendly—especially after a few tens of millions of years go by.”
Deanna shrugged. “Suppose this atmosphere is being created right now by life so alien that our sensors simply couldn’t recognize it as life?”
“According to Eviku, that’s still just barely possible,” said Pazlar. “But it isn’t likely. Life processes, even extremely exotic ones, must involve some sort of metabolism that takes advantage of natural energy gradients—that is, materials moving from a high-energy state to a lower one. Predictable patterns of internal order being created in exchange for increased external entropy. But we simply haven’t seen anything remotely resembling that here.”
Riker nodded toward the blue world on the screen. “So nothing is maintaining this world’s atmosphere. Or at least nothing we’ve detected so far.”
“That’s right,” Pazlar said. “In fact, Chamish and Bralik have both confirmed that the oxygen in the atmosphere is slowly combining with the surface through natural weathering processes, even as it’s being broken down by exospheric solar ultraviolet radiation. Since no detectable process is acting to maintain the atmosphere, it will succumb given enough time. Most of the free oxygen will end up in the rocks, and much of the rest will ultimately bleed off into space.”
“In other words,” Riker said, “what looks nominally like another Earth now will someday deteriorate into another Mars.”
“Assuming that the atmosphere’s rate of deterioration remains relatively consistent over time, it should be possible to estimate the approximate age of this . . . non-biogenic atmosphere,” said Tuvok, who had raised an eyebrow. Though the phlegmatic Vulcan’s current post was tactical officer, it seemed obvious to Riker that his scientific curiosity was now fully roused.
“My department thought the very same thing,” said Pazlar. “Bralik locked the core probes onto the rock strata that corresponds to a time-depth of about five million standard years. And that’s where we’ve found a marker of sorts—just not a marker made by life.”
“What sort of marker?” Deanna asked.
“A very thin layer of klendthium that seems to cover the entire planet at that depth,” Pazlar said.
Riker nodded. “The same way a subsurface layer of radioactive iridium marks the asteroid collision that wiped out the dinosaurs on Earth around sixty-five million years ago.”
“Exactly,” Pazlar said with a nod.
“Klendthium,” Tuvok repeated. “That is an extremely rare mineral that I have only seen associated with Vulcan terraforming techniques, such as the ones historically employed at the Loonkerian outpost on Klendth.”
Hence the name, I suppose, Riker thought.
Deanna turned to face the tactical station. “Other cultures have employed methods similar to the Vulcan universal atmospheric element compensator, Commander. Vulcan is only one of that technology’s more recent users.”
“Quite right,” Pazlar said.
“It sounds as though you think we may have found another,” Riker said.
“Wait a minute,” Vale said, waving her hands before her