Sunday, April 20, 2014

(Mostly) Water Worlds

Imagine a super Earth that is mostly covered in water. Landmasses are few and scattered. What would be the consequences for the development of an advanced civilization?

Landmass Size

For development of an advanced civilization on a super water world, I think it would have to be a water world where the landmasses are not miniscule. Tiny scattered islands would not give much evolutionary chances, or pressures, for life to leave the ocean (there would be but one ocean on a water world). What benefit would there be? There would not be enough territory for land creatures to have a go at it. There may be creatures that learn to live in the shallows, and there would probably be more shallow areas than areas above the ocean surface; and those creatures may venture at times on the land. Maybe some would evolve to use the land to lay eggs - protection from egg eaters. Some plant life that survive on the surface of the ocean could also end up being OK on the tiny islands - being small land masses, on a very large water world would mean waves, storms, rain, as well as a humid atmosphere (we suspect super Earths would have thick atmospheres, and may be steamy or humid). This atmosphere would potentially offer more protection from ultra violet radiation than our atmosphere, making it easier for surface water plants to survive periods on the land masses.

But for larger land masses - large enough to support evolution of land creatures - that is a different tale. Large land masses allow room for life to evolve permanent settlers, for a complex enough, and large enough, ecosystem to allow for permanent land adaptation. Once life evolves species to permanent adapt to land, they can then spread to smaller, relatively nearby, landmasses.

Landmass Separations

On a super Earth, even large land masses, close to Earth continents in size, would be separated by vast stretches of water - a vastness that would make our oceans seem like large lakes by comparison.

On Earth, landmasses separated for long periods show us divergent evolutionary paths. Each continent on a super Earth water world would have little biological communication with each other, at least for creatures that become fully established as land creatures. Semi-aquatic could eventually find their way to other landmasses, but those that evolve to be on land - each landmass would be a separate evolutionary laboratory.

An Aside

I have to stop for a moment here. While the evidence for evolution is overwhelming, it still has its holes, and thus it needs refining. But I also think that the Grand Designer of the universe has created the marvelous, awe inspiring, supremely elegant and beautiful natural laws that brought the universe to life. It's a sonnet, controlled by some regulations and restrictions, but allowing for so much expression within. For me, evolution is not anti-spiritual, but is evidence of a grand design, a remarkable design, that allows for such an incredible range of life in this universe. Many, many different songs of life, a Universe Symphony. And so, as science uncovers more truths of the universe, we will learn more of this Grand Design, and discover more of the beauty, the genius, the elegance of the Universe. This outlook informs my speculations. See "Introduction" for more on this blog's focus.
Evolutionary Laboratories

While the landmass lifeforms will have evolved from the same one ocean, the greatly separated major landmasses would allow for different evolutionary paths. Convergent evolution, where organisms not closely related (not monophyletic) independently evolve similar traits, would come into play, of course: lifeforms evolving similar adaptations because the occupy similar niches such as climbing trees, hunting at night, and eating burrowing insectoids. They would be on the same planet, within that planet's gravity well, magnetic field, and living through the planet's seasons as it orbits its star. But there will be variations in how each landmass' lifeforms specifically adapt. Natural disasters may affect one landmass while another is barely even touched by it - for instance, a supervolcano exploding on one landmass, but as the planet is a super Earth, and the landmasses greatly separated, the devastating effects of a supervolcano on this super Earth would not have the same global impact as a supervolcano explosion on Earth would. A meteor strike on a super water world would have less of a global impact, for the same size meteor, as that strike would on the Earth. A tsunami from an ocean strike would have much further to go, on a world with higher gravity, dissipating more of the tsunami's energy by the time it strikes a landmass than it would on the Earth. Not that there still would not be global effects from major disasters, it is just that with vast distances between at least some of the landmasses the effects for some areas of the planet would be much reduced. This would allow for very different end results. 

Dinosaurs Kingdoms and Mammal Kingdoms?   

If the Earth was a super water world, where it had, say, the same overall landmasses but with much, much greater distances between some of them due to the vastness of the global ocean, one result is that one continent would still have dinosaurs evolving, while another continent would have the dinosaurs wiped out, and the mammals evolving. Would this result in a sentient warm-blooded dinosaur race (probably feathered) on one continent, and sentient warm-blooded furry mammal race on another continent - intelligent descendants of the dinosaurs ruling one continent while intelligent humans ruling another? If the dinosaurs were not wiped out, could they have continued evolving, surviving the changing Earth to become sentient? Birds are the descendants of dinosaurs. Some birds, like crows, have brains twice the size needed for control of their bodies - they are much smarter than the other birds. Some even make tools (Caledonia crows can take a twig, strip it, and then work it until it has a hook at one end so that it can use it to hook insects burrowed in holes). If the dinosaurs were not wiped out by natural disaster(s) (some think more than one disaster ended their reign), could some have evolved to human level intelligence? 

What a world that would be. One day, an explorer from the dinosaur kingdom coming across the human kingdom, or vice versa.

Exploration

Which leads to my next speculation for this long post. For a world where continents are separated by distances many times what our continents are separated by, what would that mean for exploration? A sentient being is probably a curious one, and with a need to do some exploring, expanding territory. 

But as we see from our past, a large ocean is perilous to traverse. Many of our ancestors still did - we are finding that they traveled more, and farther, than we first thought. But it was perilous, and many resisted. For a continent that had only a few islands nearby and then nothing else, many early ships would leave to either never return or to return with no sightings of land. This would hold true for centuries as their sailing technology would not be enough to cover the incredible distances needed to get to another continent. The pressure to develop this technology would not be great - there is just no evidence for them, no tales of far off countries - just the known boundaries of their continent, the small islands off the coast, and that is it. The known world. The center of the world, and of the universe, as known to them. 

This separation, this loneliness, would allow the separated sentient beings on the separated continents to progress on their own, focusing on their known world, their center of the world. Until one day at least one progresses to the point where they can begin to think of exploring the universe. As knowledge increases, as they being to realize their world is a giant sphere, they may again wonder if some continent lies far, far away, just like we use to wonder if sentient life existed on Mars, or the Moon. Scientific exploration leads to technology that finally enables them to send a probe around the planet, or a long range probe to cross the seas (though a planet orbiting probe is the much more efficient means), and they spot it - another continent. 

Contact

And now the final speculations for this long post What myriad of ways that could play out? A civilization more advanced but for some reason didn't launch an orbiting probe (their culture focused more inward for whatever reasons - political,  theological, or distracted by a more harsh environment and needing to spend more energies there). Or a civilization less advanced. People similar in body form, but still different enough: humanoid but with tails, or humanoid but much smaller. Or more aggressive. Or not humanoid at all. The first contact hidden by the government of the country that sent the probe because of the differences - delaying actual contact. Or used by the government to rally their dissafected people against a perceived enemy?  Or this other land thought of as being heaven, or hell, or .... So very many different ways that first contact could play out.

Wednesday, September 5, 2012

Very Elliptical Orbits and Possible Life


As Spock Would Say?

From time to time I read about how planets in very elliptical orbits, orbits which take the planet in and out of the star's habitable zone, will probably not harbor life. Just too extreme. Of course if such a planet can support life, it would be, as that saying by Mr. Spock goes "it's life, Jim, but not as we know it." (Yes, I know that the line was not spoken by Spock in the series, but only in The Firms' song "Star Trekkin.'") But wait a minute. In pondering the report mentioned in the Creatures Frozen for 32,000 Years Still Alive post below maybe we should revisit those assumptions.

Or Not

Bacteria have been found buried deep in solid rock - bacteria with very slow metabolic states and are probably thousands of years old. Penn State scientists discovered in Kalaallit Nunaat (Greenland) dormant ultra-small bacteria (Chryseobacterium greenlandensis) trapped 2 miles deep in 120,000 year old ice core samples. If Earth creatures can reanimate after being frozen for tens of thousands of years, if other Earth creatures can last for hundreds of thousands of years, or even millions, then 1) life can be possible in very elliptical orbits and 2) it still could be life as we know it. We have many example of extreme life on Earth, living under conditions scientists not long ago said were not able to support life: from deep in antarctic ice, to miles below the surface of the Earth, to boiling hot springs, to volcanic vents on the sunless depths of the ocean floor, to acidic mine drainage, to the stratosphere -- life is everywhere on this planet, and in many, many forms.

Kol-Ut-Shan, as Spock Would More Likely Say

So, is it truly implausible that life can evolve on planets that orbit in and out of the habitable zone? Evolution may possibly take longer, but the most common star, the red dwarf, develop very slowly, lasting up to hundreds of billions of years. Plenty of time for life to evolve and in its own fashion thrive. Most of the time we put a limit on where life can exist on the Earth, we later find we are wrong.

Maybe we should embrace the Star Trek Vulcan philosophy of IDIC: Infinite Diversity from Infinite Combinations (Kol-Ut-Shan according to an episode of ST: Voyager). Though if life has universal laws (like physics and chemistry, on which biology depends), I am not sure about the Infinite part. Natural laws do have some limits, boundaries, ranges. But  even so, the range of diversity that can arise is still vast. Maybe it should have been ADAC: Astronomical Diversity from Astronomical Combinations. Or IDAC: Incredible Diversity from Astronomical Combinations. Of course, it is a trivial difference to be concerned over.
 
What matters is that there is an incredible array of life on this planet. Especially if we not only consider all the varied environments life can be found now on Earth, but all the varieties of life that have existed in all the varied Earth environments (some radically different) in the past as well. An incredible, astronomical diversity. 


Reference:

Coghlan, Andy. "'Resurrection Bug' Revived after 120,000 Years." Life. New Scientist. 15 June 2009. Web. 30 July 2009. <http://www.newscientist.com/article/dn17305-resurrection-bug-revived-after-120000-years.html>

Helmuth, Laura. "Top Ten Places Where Life Shouldn't Exist... But Does." Science & Nature. Smithsonian Magazine. 13 October 2009. Web. 5 September 2012. <http://www.smithsonianmag.com/science-nature/Top-Ten-Places-Where-Life-Shouldnt-Exist-But-Does.html#ixzz25e81Ip2i

"IDIC" Memory Alpha, The Star Trek Wiki. n.d. Web. 5 September 2012. <http://en.memory-alpha.org/wiki/IDIC>

"Novel bacterial species found trapped in Greenland's ice." Penn State Live. Penn State University. 3 June 2008. Web. 30 July 2009. <http://live.psu.edu/story/31052>

Sunday, July 1, 2012

New Technique to Weigh Planets

New Technique to Weigh Planets

Summary: For the first time, scientists have developed a method for determining the mass of non-transiting exoplanets. The research could even lead to techniques for detecting molecules associated with the presence of life on such worlds.

Saturday, April 14, 2012

Exoplanet Study Suggests our Solar System is the Norm

Astrobiology Magazine








Exoplanet Study Suggests our Solar System is the Norm
Source: Centro de Astrofisica da Universidade do Porto press release


Cosmic Evolution  Posted:   04/14/12


Summary: A new study reveals that planetary orbits around Sun-like stars have a tendency to be strongly aligned, similar to the disk-like alignment of the planets in our own solar system.




 
Exoplanets with non-coplanar orbits.
Credit: Ricardo Reis, Centro de Astrofísica da Universidade do Porto
Recently, the HARPS spectrograph and the Kepler satellite made a census of the planetary population around stars like our own, revealing a bounty of planetary systems. A follow-up study lead by members of the EXOEarths team (Centro de Astrofísica da Universidade do Porto -- CAUP), in collaboration with Geneva University, did a joint analysis of the data which showed that the planetary orbits in a system are strongly aligned, like in a disk, just as we have in our own solar system.

The two most effective methods for detecting extrasolar planets are the radial-velocity method and the transit method. The radial-velocity method detects planets through the reflex motion induced by the planet on the star’s velocity on the radial direction (hence the name). This velocity variation is detected through the Doppler effect, the same that leads to a pitch change in the sound of an traveling ambulance. On the other hand, a planetary transit is akin to a mini-eclipse. As a planet travels around the star, its orbit can locate it in front of the star, and the light we collect from the star is reduced because the planet blocks part of it (even though we cannot image the planet).
Astrobiology Magazine

Saturday, January 28, 2012

The Elusive "Wow!"

The Elusive "Wow!" - What We Do | The Planetary Society
The Quest for the "WOW!" - One Man's search for SETI's Most Promising Signal

Review of Robert H. Gray, The Elusive Wow: Searching for Extraterrestrial intelligence (Chicago: Palmer Square Press, 2011). A Radio SETI update by Amir Alexander. January 27, 2012.

<http://www.planetary.org/programs/projects/seti_radio_searches/20120127.html>