Desperately Seeking Life Beyond Earth
Earth life cannot be unique. How about you, Mars? Europa, anything? Enceladus? Comet 67P? Please break the silence!
The latest evidence-starved speculation about life beyond Earth is that Rosetta’s lander Philae is sitting on a world sculpted by microbes (see PhysOrg). The speculation comes from long-time panspermia advocate Chandra Wickramasinghe who, with the late astronomer Fred Hoyle, made arguments in a book Evolution from Space (1984) that Earth was seeded with alien life by comets. The notion even got favorable press by the Royal Astronomical Society. No direct detection of life has been forthcoming from Comet 67P. Wickramasinghe speculates from the shape of formations on the surface.
In Reality Check mode, planetary science professor Monica Grady on The Conversation writes, “Tempting as it may seem, there’s no evidence to suggest life on Comet 67P.” Her reason: other processes can explain the surface features, and “The chance that life could flourish on a freezing body with no sunlight or oxygen is in fact vanishingly small.” She jokes that some sun-struck scientists must be bored with nothing else to think about:
The origin of life on Earth is not fully understood, but we are making great strides towards recognising the mechanisms that make up each stage. Placing those mechanisms in an unknown environment and suggesting that life on Earth was seeded by microbes on comets solves nothing. It merely moves the problem further away, making it even harder to study.
Is it a slow summer? Are we already fatigued by the heatwave which lasted a couple of days? I suppose if there is nothing else to worry about, then we can ponder the chances of finding alien life beyond the Earth. Now, what’s that Curiosity Rover up to on Mars?
While Grady considers the probability of life vanishingly small for a comet, she apparently does believe that life could appear in more conducive habitats, like on Mars. That belief is seen in a TED talk by Nathalie Cabrol (SETI Institute), reported by Elizabeth Howell on Astrobiology Magazine. “Earth and Mars could share a life history,” the headline reads. Surprisingly, Cabrol believes that history could be more readable on Mars than on Earth. “Mars might hold the secret to the origin of life,” she tantalizes. Like most astrobiologists, Cabrol thinks that finding microbes in extreme environments on Earth can inform speculations about its presence on other worlds. Despite her SETI affiliations, she would be content to detect microbes out in space. Beyond Mars, she imagines Enceladus (she pronounces it like enchilada) like a giant spa, incubating life. From Mars, Cabrol leaps to other places in the solar system and into the big questions: where did we come from? Our generation, she promises, can answer these questions. “This can be our achievement; this can be our legacy, but only if we dare to explore.” She even managed to bring the subject of climate change into her talk.
Darwin skeptics got a big laugh at philosopher Michael Ruse’s expense when, in the documentary Expelled (2008), he speculated that life began on the backs of crystals (YouTube). Unashamedly, PhysOrg continues that new-agey tradition with its headline, “Martian gems could point to evidence of life.” Striving to be a little more empirically robust, researchers at the University of Glasgow (where once Lord Kelvin challenged Darwinism) perform their divination on the Nakhla meteorite, looking for opals that are analogous to Earth opals that form around hot springs. From there, a leap of faith is required: “Closer study of Martian opals by future missions to Mars could well help us learn more about the planet’s past and whether it once held life.”
While physicists are struggling to explain the long-term heat output from the geysers erupting on Saturn’s small moon Enceladus (7/06/15), others merely assume that water and long periods of time gives birth to life. Space.com‘s entry “What’s inside Saturn moon Enceladus? Geyser timing gives hints” deals primarily with inferences about the interior from observations of surface activity at different points of the orbit. But the l-word life makes its appearance twice: “Scientists believe a liquid-water ocean exists beneath the solid surface, and that life could potentially survive there.” Later, “Understanding more about the geysers of Enceladus would shed light on the alien moon’s interior and on whether or not life dwells there, said Cassini imaging team leader Carolyn Porco.”
Volcanos might seem unlikely places to hunt for life, but Astrobiology Magazine is convinced they are the best places to look. “Atmospheric signs of volcanic activity could aid search for life,” their article reads. A convoluted chain of reasoning begins with volcanos, assumes volcanism is a proxy for plate tectonics, proceeds through outgassing, and assumes if the right gases are present on a planet, life could exist, too. Amit Misra (U of Washington) carries the ball to the goal line: “What this means is that if we can detect a volcanic eruption on a planet, and if it meets other criteria like being in the habitable zone, that planet should move up our list of potential targets to search for life.” Problem: Venus, Mercury, the moon, Mars, and Io all have (or have had) volcanoes, but neither have plate tectonics nor atmospheres suitable for life. The list of “other criteria” for life is getting long (see 8/14/15 commentary).
In a cosmic “call to arms,” University of Washington astronomy professor Julianne Dalcanton is calling on astronomers to advocate for a new “High Definition Space Telescope” (HDST) whose primary purpose would be to detect atmospheres of exoplanets where life might exist. “The goal is not just to find watery planets with rocky cores,” Dalcanton says in an article on PhysOrg. “We want to find atmospheres that have been shaped by the presence of life.” She thinks that an atmosphere “left to its own devices” would not have both oxygen and methane, for instance. This would be a clue to the presence of life. Why the motivation? If a methane-oxygen atmosphere is found, “That would be an unexpected combination for a lifeless planet, and a sign that Earth is no ordinary world.”
Hoyle’s ideas on panspermia may be philosophically and empirically challenged, but he presented one of the strongest logical and mathematical proofs against the origin of life by chance (after his calculations, he came up with the “tornado in a junkyard to a 747” analogy). Yet even the famous astronomer could not get a respectful hearing on that point. Darwin skeptics have been hammering on the improbability of life’s origin by undirected natural causes for decades (see our online book as one example). The Wistar Institute study made little difference. The Mystery of Life’s Origin didn’t make much of a dent, either, other than stimulating the Intelligent Design Movement. Stephen Meyer’s excellent book Signature in the Cell stands unrefuted. Despite all this empirical and logical evidence, the unfeigned faith of the Darwinian astrobiologists continues on as if nothing happened. This is the sad state of affairs when ideology takes on totalitarian powers, and corrupts a government willing to pour millions of dollars into the pockets of its priesthood.