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At long last my philosophical novel is complete! A journey through space, time, and dreams, Planetary Messenger explores the social, scientific, and spiritual consequences of discovering another planet in the galaxy just like our Earth. I began this project as a NaNoWriMo entry in 2007 and continued editing and revising for a year and a half.
From the back cover:
Since the dawn of humanity we have gazed at the stars to ponder our existence. To the naked eye the skies are dark and lifeless, but what if, through a glass, we looked to the heavens and saw our mirror image, a twin Earth from afar? If we found our uniqueness shattered in the vast cosmic arena, then what, if anything, could we still hold sacred?
Planetary Messenger is now available either directly from Createspace or through Amazon. Thanks to all of you who have been part of my life so far and helped make this possible. Happy reading!
I’ve always known that the Kuiper belt and Oort Cloud are the outermost part of the Solar System, but I never had a sense of scale between the two. Kuiper belt objects, including Pluto and other dwarf planets, orbit at ~55 AU (0.001 light years). Compare to the Oort Cloud, a 50,000 AU (~1 light year) sphere containing billions of comets at the boundary of the Solar System’s gravitation.
We have hardly begun to explore the outer Solar System and Kuiper Belt, and have searched next to nothing of the Oort Cloud–analogous to only inspecting your garden box in a 100 acre plot of land. If extraterrestrials are observing us from the Oort Cloud, we have absolutely zero chance of knowing they’re here.
Venus today is far too hot to sustain surface liquid water or any biology requiring it, but did Venusian life exist in the past? Nearly all remains of past life would have been destroyed by now, but it is plausable–and perhaps likely–that Venus once boasted Earth-like oceans. This possibility exists because the sun may not have been as bright in the past.
Models of stellar evolution predict that a star brightens by about 30% over it’s main sequence lifetime due to core contraction as the star fuses hydrogen into helium. The inference of warmer-than-present temperatures for the early Earth despite the reduction in solar luminosity is known as the faint young sun paradox (one of my research interests). Earth seems to have sustained both liquid water and life for nearly 4 billion years, continually maintaining habitable temperatures.
So what happened to Venus? Eventually the surface received enough energy to evaporate the oceans and enter a positive feedback known as a runaway greenhouse. Today, we see a cloudy world with sulfuric acid rain and a surface hot enough to melt lead. But 4 billion years ago life could have arisen in the Venusian oceans and perhaps even lasted long enough to develop intelligence.
I can imagine a Venusian scientist carefully working out models of stellar evolution–only to find that their parent star was slowly and steadily brightening! We look back in time and find a faint young sun paradox, but the Venusians would have a contemporary warming sun catastrophe! The greatest climate disaster in the history of our solar system may well have been when Venus entered its runaway greenhouse state to become uninhabitable.
Technologically advanced civilizations in the galaxy may be short-lived because they inevitably destroy themselves, but perhaps extraterrestrials haven’t contacted us because they’re too introspective for space exploration:
One problem might be conflict resolution before they wipe themselves out. One problem may be a loss of interest. They might turn to internal religion, like Zen Buddhism, emphasizing the here and now.
From “The Lifetimes of Technical Civilizations” by Shklovsky, Platt, Stent, Minsky, & Gold in Communication with Extraterrestrial Intelligence (Sagan, 1973)
This past Wednesday Col Maybury, host of the Australian radio show The Starlight Zone, interviewed Shawn and I about covering the far side of the Moon with mirrors as a remotely detectable technosignature.
Listen to the complete (~5 minute) interview at the Starlight Zone
This idea got far more press than either of us had anticipated, so we tried to use our air time to do some damage control and clarify the idea beyond the scope of a brief news write-up. We are currently in the process of drafting the manuscript for submission.
This work is unfunded: We came up with this idea following the Pale Blue Dot III meeting as a solution to particular problems with the SETI approach to finding intelligence; however, we are not funded to develop this idea nor do we have any intentions of proposing construction of mirrors on the Moon to any funding agency. (Our global society can’t even agree upon a consistent program to address climate change issues–I seriously doubt our ability to maintain a long-term signaling project.)
Our signal is omnidirectional: A targeted broadcast such as a radio signal or laser pulse is limited because of its directionality. Our scheme, though, covers the far side of the Moon with mirrors on pivots (with dark solar panels on the opposite side) so that the albedo of the Moon can be effectively changed from 0 to 1, resulting in a 20% change in luminosity for the Earth-Moon system. This change in luminosity will be observable from almost any direction at any time and will not require a targeted broadcast.
Our signal is broadband: Because the light reflected from the Moon’s mirrors comes from the Sun, the detected change in luminosity will span a large section of the electromagnetic spectrum (depending on the particular mirrors used). This further increases our chance of success because we make fewer assumptions about the preferred observational/communicative frequency of extraterrestrials (whereas conventional SETI presumes radio beacons or other narrow-band broadcasts).
This beacon requires current and near-future technology: The mirror/solar panel pivots can be constructed with current technology. Furthermore, we are detecting new extrasolar planets every day. In 2009, Kepler will launch in search of terrestrial planets around other stars, and in the next 10-20 years the Terrestrial Planet Finder will be able to observe these planets and take spectra of their atmospheres. In other words, within the century it will be within our technological grasp not only to build such a signal but also to detect a similar signal around a distant world.
ET’s may use a similar technique: Even if we never construct a technosignature using the Moon, it is conceivable that a technological extraterrestrial society may signal their presence using a similar method. If the Terrestrial Planet Finder were to detect an Earth-sized planet around another star blinking in the prime numbers, we would at least have a hypothesis to explain this seemingly deliberate signal.
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