This article is a companion piece to Who’s Out There-Anyone? A Review March
The March 2019 National Geographic article (reviewed here last month) “Who’s Out There” by Jamie Shreeve is a grand summary of how we humans are searching for others and how we might make contact. His claim that “new discoveries” suggest that we are not alone is challenged by an article in Scientific American September 2018, discussed here. Meanwhile, lets review briefly some of life’s indicators that have been mentioned recently in other studies.
Planetary life might be indicated on an exoplanet that had a “vegetation red edge”–the contrast of spectra from the absorption of red light and the reflection of near-infrared light. Other vegetation might look different (appear lavender in color) if, instead of chlorophyll, they were to use retinal pigment for photosynthesis.
Life could be likely if oxygen, carbon dioxide or methane were found in an exoplanet’s atmosphere, absorbing tell-tale wavelengths. Meanwhile, plans are being made for laser beams to propel tiny spacecraft up to a fifth the speed of light. They could reach our nearest neighbor Proxima Centauri B in twenty years. That’s a long time.
I wonder if it’s worth the effort, given the current concerns we face here on Earth. We could be quite alone out here. The article in September 2018 Scientific American outlines why. The authors point out that “We are here because of a long chain of implausible coincidences.” Other planets have apparently not been so lucky, given what Kepler and TESS have been finding.
The Scientific American “implausibles”: 1– Many stars died to produce the two percent metals in our sun–not too little and not too much so its rocky planets, including Earth, could form. 2– We are in a galaxy about 100,000 light years across. We are 27,000 light years, halfway, from the rim, so there are fewer supernovae and gamma-ray bursts to
worry about. The galactic habitable zone is about 7 % of the “galactic radius and contains less than five percent of the galaxy’s stars.”
3– Our fellow planets in near-circular orbits provide long-term, non-chaotic stability for us. 4– Earth orbits the sun where water is liquid, temperatures are mild, and the magnetic field repels nasty radiation. 5–Earth’s large magnetic core and rapid rotation create a strong magnetic field to protect us from cosmic radiation–thanks to the
moon formed when a Mar’s-size object hit Earth. This knocked out Earth’s light matter, thinned its crust and formed the moon, which now acts as a stabilizer as we orbit the sun.
6–Plate tectonics and the moon distribute nutrients (especially carbon) and stabilize temperatures. 7–The moon also prevents our axis from tipping too far off its axis. 8– Single-celled organisms took only a billion years to evolve, but then they got together to form our complex cells, necessary for the complexity of our lives. 9–We intelligent
critters managed to avoid extinction several times. We were reduced to nearly just a few hundred 670,000 and again 150, 000 years ago.
Lots of the exoplanets Kepler and TESS have found don’t have moons or plate tectonics or circular orbits just far enough from their sun to be comfortably warm. They may not have a magnetic core or rapid rotation, and they may not be in the lucky 7% of their galaxy, as we are.
Time and energy and distance are not our friends when it comes to being realistic about travel through the Milky Way–much less travel to other galaxies. We are very lucky to live in such a verdant, gorgeous place. It’s time to realize how we have taken it for granted, and how we have abused it. Time to pay attention to planet Earth, the only home we will ever have–at least, most of us.
The more we learn about the history of life’s apparent one-time beginning on Earth and its current complexity, its imperfections, and its vulnerabilities–the more unlikely it seems that life happens willy-nilly everywhere (or anywhere else) in the universe. We seem to have been extremely lucky here on this verdant beautiful Earth.Surely,
at the very least, we could use a wake-up call to appreciate what we have, before we overuse and waste it all.
For example, we could continue to explore Mars with robots and forget expending too much money sending live humans there. Robots are more robust and just about as smart. Drilling through meters of ice to find life on our near neighbors and their moons does not make as much sense as first looking for the four basic signs of life–electron donors and receptors, Carbon and water. Europe would be a good place to start, if we care anything about preserving essential resources on an Earth reeling with overuse of plastic, water, and living space. See “Michael Carrol’s thoughtful article “Voyage to the Bottom of an Alien Sea” in Discover magazine March 2019, page 56.
An article in February 2019 Scientific American “The Exoplanet Next Door” makes a case for studying Venus. It started out very similar to Earth with its active volcanoes and plate tectonics, but is now clouded with sulfuric acid now, “forbidding to life.”
When and why did Earth and Venus diverge in their abilities to foster life? Has plate tectonics recently started on Venus? Could life ever utilize its atmosphere? Could life take root there? Have we neglected its study too long?
The point of all this is a plea for more careful thought about how we use the remaining resources on Earth. Yes, we can be proud of our innovations, our knowledge, and our expertise, but we need to be mindful of Earth’s limits, while we focus our energy and our values on how we impact conditions on our home planet–a verdant and rare beauty in a
very large universe loaded mostly with uninhabitable exoplanets.
Author of The Archives of Varok
The View Beyond Earth (Book 1.)
The Webs of Varok (Book 2.)
Nautilus Silver Award 2013 YA
ForeWord IBPA finalist 2012 adult SF
The Alien Effect (Book 3.)
An Alien’s Quest (Book 4. Released Nov.21, 2016)
Excerpts, Synopses, Reviews, On Writing, Characters and More-
Reviews of significant books- www.goodreads.com/Cary_Neeper
How the Hen House Turns- www.ladailypost.com
Complexity, Bio, Bibliography and Links- caryneeper.com
Astrobiology- astronaut.com search:Who’s Out There