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>

Kepler Confirms ExoPlanet in a Habitable Zone

An exciting development - a Earth-like planet in a habitable zone (even possible that it has Earth-like temperatures). I am sure this planet will be the target of many investigations, especially as newer, more sensitive, equipment come on line.

This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star. Image Credit: NASA/Ames/JPL-Caltech

NASA's Kepler mission has confirmed its first planet in the "habitable zone," the region where liquid water could exist on a planet’s surface. Kepler also has discovered more than 1,000 new planet candidates, nearly doubling its previously known count. Ten of these candidates are near-Earth-size and orbit in the habitable zone of their host star. Candidates require follow-up observations to verify they are actual planets.

The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.

Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.

Read more of this NASA press release at: <http://astrobio.net/pressrelease/4381/kepler-confirms-exoplanet-in-a-habitable-zone>.

Life in the Infrared

In1996 scientists were surprised to find a version of chlorophyll, chlorophyll d, in a cyanobacterium (blue-green algae or blue-green bacteria) that can photosynthesize light at 710nm, just in the infrared region. How it can get enough energy to photosynthesize is a mystery right now. It is possible that it acts more like chlorophyll a, passing on the captured energy to other chlorophyll molecules which then do the actual photosynthesis.

Recently, Dr Min Chen, from the University of Sydney, discovered in cyanobacterium living inside stromatolites another chlorophyll molecule which can absorb infrared light - this time deeper into the infrared range at 720 nm. This molecule, chlorophyll f, raises the same question as with chlorophyll d: how does it get enough energy from infrared light to photosynthesize oxygen? Or does it act as a helper, passing on the energy to other chlorophyll?

While this discovery has implications for biotechnology and bioenergy, it also has implications for life on other planets. As Dr. Chen remarks:

the fact that we have discovered a cyanobacterium that exploits a tiny modification in its chlorophyll molecule to photosynthesise in light that we cannot see, opens our mind to the seemingly limitless ways that organisms adapt to survive in their environment.

This helps expands the environmental range where we can look for life. For instance, it helps increase the possibility of life arising around class M stars (see Color of Life for more information). Yet more evidence that Dr. Ian Malcolm's (Jurassic Park) adage is correct: life will find a way.

Reference:

Chen, Min, et. al. "A Red-Shifted Chlorophyll." Science Magazine. 19 August 2010. Web. 21 August 2010. <http://www.sciencemag.org/cgi/content/abstract/science.1191127>

Europa's Liquid Ocean May Be Oxygen Rich

New research suggests that there is plenty of oxygen available in the subsurface ocean of Europa to support oxygen-based metabolic processes for life similar to that on Earth. In fact, there may be enough oxygen to support complex, animal-like organisms with greater oxygen demands than microorganisms.

Europa's ice cyclically renews - the top crust is only 50 million years old, replenished by water from below coming through  fissures. This cycle brings into the under-ice ocean surface oxygen produced by energetic charged particles. The rate is faster than oxygen build up in Earth's oceans - thus Europa's ocean may be able to support more complex creatures than was once thought. And, importantly, this buildup had a delay; oxygen is actually toxic to pre-biotic chemistry. Life, as we know it, needs the early pre-biotic chemical process to happen without the damaging effects of oxygen.

We need to send probes to Europa. If we find life there, it will be strong indication that 1) life can form outside of the Godilock's Zone, or the Habitable Zone and 2) life can form on icy moons orbiting gas giants. Since icy moons orbiting gas giants may be more common than small terrestrial planets orbiting in the HZ of its parent star, it means that we should not ignore gas giants when looking for extrasolar life.

Reference:

"Jupiter's Moon Europa Has Enough Oxygen for Life." PhysOrg.com. PhysOrg.com. 16 October 2009. Web. 16 October 2009. <http://www.physorg.com/news174918239.html>


Image Credit: NASA/JPL

Orange Dwarf Stars and Life - Common?

Illustration © European Space Organization

Our Dwarf Sun

Did you know that our own sun is in fact a dwarf star? It is a G type, or yellow dwarf. Next come the smaller K types, or orange dwarfs, followed by even smaller M types, or red dwarfs. While we know life has - at least once - arisen in a yellow dwarf system, could life arise on orange or red dwarf system? While the answer may be yest to both, some think that orange dwarfs may actually make the best place to find life.

Types of Dwarf Stars

• Yellow dwarfs (which are actually white to yellow in color), have surface temperatures of 5,000 - 6,000 K. The average size is a little larger than our sun (110% the size of the sun).

• Orange dwarfs (orange to red in color), have surface temperatures of 3,500 - 5,000 K. Their average size is about 90% that of the sun and are 40 % as luminous as the sun

• Red dwarfs (red in color), have surface temperatures below 3,500 K. The average size is about 40% that of the sun and are 4% as luminous as the sun. Red dwarfs are by far the most common star, accounting for over 75% of all the stars in our galaxy.

Habitable Zones

As you can tell, as the size decreases, the temperature decreases as well as the luminosity. The width of the Habitable Zone (HZ), thus, decreases as well and moves closer to the star (see illustration below) . But HZs still exist. And red dwarfs are extremely long lived - up to 10 trillion years - giving life plenty of time to arise. However, there are other considerations that need to be factored in. First, some tectonic activity is needed to help control the amount of C02 as well as for mixing chemicals - life needs to arise on a chemically dynamic planet. However too much tectonic activity can wipe life out. Planets orbiting in a red dwarf's HZ may experience extreme tidal forces. Another problem with red dwarfs is that being so close to the star there can be problems with radiation bursts from the star - red dwarfs tend to be rather cranky stars that frequently flare up, releasing dangerous bursts of radiation. Since the average HZ for a red dwarf is only 0.1 to 0.2 AU away, the HZ for a red dwarf may actually not be very hospitable. By the way, the HZ for yellow dwarfs, like our sun, is 0.8 AU to 2 AUs.

The average HZ for orange dwarfs is 0.3 to 1 AU away. Its HZ is wider, allowing for planets to be further from the star and thus experience less tidal forces. Also, their flare activity is only slightly more than yellow dwarfs. Another consideration is that orange dwarfs are longer lived than our sun - they have almost twice the life span: almost 20 billion years compare to the 10 billion or so years for our sun. Their light and heat output is much more stable than the sun, fluctuating less over its life and thus making more of its long lifespan useful to life. Orange dwarfs may just give life more chance to originate and thrive than yellow dwarfs like our sun. While not as common as red dwarfs (the most common star type), orange dwarfs are 3 - 4 times more common than yellow dwarfs. We definitely should not overlook orange dwarfs when searching for extraterrestrial life.

Illustration of HZs for Dwarf Stars: dM = Red Dwarfs (M class stars), dK = Orange Dwarfs (K class stars), and dG = Yellow Dwarfs (G class stars).

© Living with a Red Dwarf Program

Red Dwarf Support

Red dwarfs do have their supporters: the "Living with a Red Dwarf" Program, established at Villanova University by E. F. Guinan and S. G. Engle. Guinan and Engle, in their presentation at the 8th Pacific Rim Conference on Stellar Astrophysics in 2008, bring up an interesting consideration: the dangerous flares "are strongly dependent on rotation, and thus age, and diminish as the stars lose angular momentum and spin-down over time via magnetic braking" (Guinan 1). What this means is that the intensity and frequency of a red dwarfs solar flares may diminish over time. Since red dwarfs are extremely long lived, that does crack open just a bit further the door of opportunity for life to find a way to arise and thrive.

Phase Locked

One interesting result of a planet orbiting in an orange or red dwarf's HZ is that it will most likely be phased locked because of the tidal forces; like Mercury is to our Sun, or the Moon is to the Earth, the planet's rotational period and orbital period will be the same, resulting in the same side of the planet always facing the star. This can create a small zone along the terminator line (where, on a phase locked planet, day and night perpetually meet) where life may be able to better survive the radiation bursts.

Related Post

For an interesting related post, see the Color of Life post which tackles the question of what color would plants be on planets circling different types of stars.

References:

Guinan, E. F. and S. G. Engle. "'Living with a Red Dwarf' Program." Summary Paper. Living with a Red Dwarf. Villanova University. n.d. Web. 18 June 2009. <http://www.astronomy.villanova.edu/lward/prcsa2008_LWARD_new.pdf>

Shiga, David. "Orange stars are just right for life." Space. New Scientist. 06 May 2009. Web. 18 June 2009. <http://www.newscientist.com/article/dn17084-orange-stars-are-just-right-for-life.html>.

Life Outside the "Zone."

As I've stated in earlier posts, I support the idea that extrasolar life may be readily found outside the traditional "Habitable Zone" or the "Goldilocks" zone around a star - the band of space around a star that is neither too cold nor too warm for liquid water to exist. This is too simplistic. Liquid water can be found outside this zone - mainly on moons circling large planets. The tidal forces of the planet on the moon can cause the moon to heat up through internal friction. This is especially true if the moon is in an elongated orbit.

How does this work? This is due to the fact that gravity decreases with distance and the gravitational pull on the near side of the moon is greater than the gravitational pull on the far side. For a moon in a circular orbit, the moon will adjust its shape to adapt to this gravitational differential, and no tidal heating will occur. But for a moon in an eccentric orbit, the gravitational differential will change rhythmically, and the moon will be kneaded like a lump of bread dough (OK, a bit of an exaggeration). This will heat a moon even if it is outside of the solar system's main habitable zone. This increases the areas in a solar system where life can form.

Recent research by Brian Jackson, Rory Barnes, and Richard Greenberg of Arizona's Lunar and Planetary Laboratory extends this idea to planets (this research will be published in an upcoming issue of Monthly Notices of the Royal Astronomical Society). Most extrasolar planets found to date circle their stars in elongated orbits. Like a moon circling a large planet, these planets circling a large star in elongated orbits will experience tidal stress, which will cause internal heating and possibly tectonic activity. This internal heating may be enough to warm the planet to where liquid water can exist even when the planet's orbit takes it outside of its star's traditionally defined Habitable Zone.

However, because the tidal heating scales with the size of the planet, for "super-Earths," terrestrial planets 2 to 10 times the size of the Earth, the tidal heating would be too great to make the planet habitable - the planet may become too hot, with many large active volcanoes.

But for Earth-sized or smaller terrestrial planets that would otherwise be too small or too cold to support life, this type of tidal heating may help them become habitable by not only warming them up so that liquid water can exist but also by causing tectonic activity which may help life to arise. Some scientists feel that the Moon was essential to the origin of life on the Earth due to the tidal mixing which helped to mix, mainly from erosion caused by the tides, chemicals from the soil with the oceans, creating the chemical soup from which life arose. The tidal forces of a star on planet in an elongated orbit may have the same result. In addition, tectonic activity helps regulate carbon dioxide.

Therefore, I believe that the famous Drake Equation may be a bit too conservative. The number of planets (or moons!) that potentially can support life may be higher than first thought.

Reference:

"Tides have major impact on planet habitability." Astronomy. Kalmbach Publishing Co. 14 Oct. 2008. Web. 31 Oct. 2008. Provided by the Div. for Planetary Sciences of the American Astronomical Society. <http://www.astronomy.com/asy/default.aspx?c=a&id=7505>.

Habitable Moons - Are They Common?

"Thetis Moon" © DigitalBlasphemy.com

Earlier posts discussed the possibility of habitable moons, including how they may increase the habitable zone of a solar system, which would then affect the Drake Equation, giving it a larger number for N (the number of civilizations we can communicate with at this time in the galaxy).

Recent work by Caleb Scharf, Columbia University's Director of Astrobiology, points to the possibility that habitable moons may not be rare - they may even be as common as habitable planets.

Take a look at our own solar system as an example. Our solar system has several moons that, if orbited the sun instead of a planet, would be large enough to be considered planets themselves. Several of them have atmospheres, and at least one, Europa, is almost certain to have liquid water - though recent articles, which will be discussed in later posts, suggest that life can exist in ice, and that, thus, liquid water may not be necessary for life to exist (though it may be necessary for sentient life to evolve).

If our system is not unusual, then it should be common for extrasolar systems to have many moons as well, some of them large enough to have atmospheres and to retain water. As we've seen in previous posts, water is found to be rather common in planetary discs and systems (¹).

However, a heat source is needed. And to the rescue comes tidal forces: tidal forces caused by the moon's parent planet which will create internal heat for the moon. This is due to the fact that gravity decreases with distance and the gravitational pull on the near side of the moon is greater than the gravitational pull on the far side. For a moon in a circular orbit, the moon will adjust its shape to adapt to this gravitational differential, and no tidal heating will occur. But for a moon in an eccentric orbit, the gravitational differential will change rhythmically, and the moon will be kneaded like a lump of bread dough (OK, a bit of an exaggeration). This will heat a moon even if it is outside of the solar system's main habitable zone. This increases the areas in a solar system where life can form.

So when we are looking for extrasolar life, we need to look at large moons as well as planets. Right now our technology allows us to detect only large gas giants. However, rapid advances will (possibly as early as this year) allow the ability to detect terrestrial planets. The ability to detect water planets is on the horizon as well. I can not say if the ability to detect habitable moons will exist in the near future, but I would not rule it out.

Notes:

1. Many chemicals are found in space, including interstellar gas clouds of sugar and of beer!

References:

Browne, Malcom W. "Alcohol-Laden Cloud Holds the Story of a Star." New York Times. 30 May 1995. 5 February 2008. <http://query.nytimes.com/gst/fullpage.html?res=990CE7D81531F933A05756C0A963958260>.

Scharf, Caleb A. “The potential for tidally heated icy and temperate moons around exoplanets.” Astrophysical Journal. 648 (2006) 1196-1205.

Introduction to The Drake Equation

The Drake Equation

I really shouldn't go on without at least an introductory mention of the famous (and controversial) Drake Equation created by Dr. Frank Drake in 1960.

Dr. Drake's equation is a tool for estimating the number of intelligent advanced civilizations presently in the Milky Way galaxy that we would theoretically be able to communicate with.

The Drake Equation is

N=(R)(fp)(ne)(fl)(fi)(fc)(L)

where N is the number of civilizations we can communicate with at this time in the galaxy, and where:

• R = average star formation rate (10/yr)
  
• fp = percent of those with planetary systems (50%)
  
• ne = average number of planets that can potentially support life per star with planetary systems(2)
  
• fl = percent of the above planets where life actually begins - life started on Earth very quickly, water and the complex organic building blocks for life are common in the universe (100%)
  
• fi = percent of habited planets where intelligent life evolves (1%)
  
• fc = percent of intelligent life that develop communication technology capable of transmitting into space(1%)
  
• L = lifetime of all such civilizations on a particular planet - civilizations may collapse and rise again, or nearly wipe themselves out and the survivors rebuild (10,000 years)

The values in the parentheses are Dr. Drake's estimations. Using Dr. Drake's original values we arrive at N=10. As new data rolls with increasing frequency, these values tend to change. For more discussion see below. 

Assumptions

• Liquid water is required for life, 
• type M stars are too cool, 
• type O and B stars are too short lived, 
• life will develop if given a chance, 
• developing intelligence gives a survival edge, 
• and technologically advanced civilizations do not consistently prematurely destroy themselves because of their technological advances (global atomic war, for instance).

R, fi, and ne Discussion

As mentioned above, as new data rolls with increasing frequency, these values tend to change. Presently, the value for R is thought to be 6 per year. And, as mentioned a few times before in other postings in this blog, we are increasingly discovering certain intelligent traits first thought to be reserved just for humans cropping up in other animals: birds that make and keep tools, ferrets purposefully lying, and dogs mapping language to mention just a few. This indicate that the first estimation for fi (a mere 1%) may be too low.

If, however, sentient, intelligent life is so rare that we are the only one in the galaxy, or even the universe, then the vale for fi may be infinitesimally small. But, if we are the average result of habitable planetary system, and if life is found to have once existed on Mars, and to exist on Europa, then the value for fi becomes 33% (and ne becomes 3). That life formed quickly on Earth, a wet rock orbiting an average star in a nondescript part of the galaxy, then maybe, just maybe, it can form in extrasolar systems as well.

Calculate N for Yourself

See the Drake Equation Calculator on the right. Type in your own values for the variables in the Drake Equation to calculate N.

Habitable Zones and Habitable "Hot Spots"

Personally, I believe the habitable zone estimates are a bit conservative. For instance, Jupiter's moon Europa, despite being outside of our solar system's Habitable Zone, may have liquid water beneath its icy surface, and many scientists feel that Europa could support life. Thus, Habitable Zones could actually be larger, or a system could have Habitable "Hot Spots" (which includes not only planets, but large moons as well) in addition to its Habitable Zone . Maybe even an occasional type M stars could have habitable planet (see Color of Life for some discussion about life in a M class star system).

In addition, the equation does not take into account life that is spread to other planets by advanced civilizations (whether unintentionally from exploration or purposefully from terraforming). And finally, life is constantly surprising us with its great diversity here on Earth - our definition of what is life may need to be expanded.

Additional Drake Equation Posts.


Reference:

Schilling, Govert and Alan. M. MacRobert. "The Chance of Finding Aliens." SETI: Searching for Life. Sky and Telescope Magazine. 15 January 2008. <http://www.skyandtelescope.com/resources/seti/3304541.html>


Image credit: © Lynette Cook

Blackbody Radiation Exercises

No, not talking about a cosmic Jack Lalane (OK, too old of a reference). At my first alma mater, the University of Tennessee, Knoxville, the physics department has a java applet online that demonstrates why hot stars look blue and cool ones look red using Planck's Law, Wien Law, and Steffan-Boltzmann Law. It calculates the blue-visual and ultraviolet-blue color index, as well as showing where the normalized intensity lies in the ultraviolet - visible - infrared spectrum. This site is found at: <http://csep10.phys.utk.edu/guidry/java/wien/wien.html>.

I found it interesting that as a star gets hotter, its normalized intensity peak lies increasingly in the UV (ultraviolet) range of the spectrum. As stars get cooler, the peak moves toward the infrared, but doesn't get into the infrared except for very cool stars.

This would mean that for hot stars, UV would be the more important wavelength to use, while for cool stars, infrared could have some importance. Our eyes are centered around the normalized peak for the sun, with it's 5,780 K surface temperature, which makes logical sense. For beings on a planet around a blue star, their eyes could be centered in the UV band. They may not even have much use at all for the "visible" part of the spectrum ("visible" to us).

For plants, I wonder if this would mean they would be white, since they'd be using the UV photons for photosynthesis instead of our visible light range they'd reflect back all of the visible (to us) light - thus they would appear white. However, it seems unlikely that UV light photons could conceivably be used for photosynthesis. UV light is very energetic, and thus, for the most part, very damaging to life: UV inhibits photosynthesis in present day Earth plants and it can cause destruction to DNA as well as many proteins and lipids. The shorter the wavelength, the more energetic and the more damaging. However, it is thought that UV was an important source of energy in the creation of life and some viruses, bacterium, and fungal spores are rather highly resistant to UV radiation. However, often times creatures that are highly resistant to UV radiation are resistant because they have developed a mechanism for repairing the damage done by the UV radiation, and not because they can just ignore it.

Thus, there are limits to what carbon-based plant life can tolerate with regards to UV radiation. And for a planet around a particularly hot blue star, life would definitely have to find a way to deal with the UV radiation (here's a thought: if UV is thought to be important to the origin of life, would that mean that life is more likely to originate around blue stars than for other stars?). There are two articles, "Limits of photosynthesis in extrasolar planetary systems for earth-like planets," by S. Frank et al. and "Ultraviolet radiation constraints around the circumstellar habitable zones," by Andrea P. Buccino, et al. which I hope to get my hands on soon. Part of the Habitable Zone equation may not only include the zone where water can be in a liquid state, but also where UV radiation isn't extreme.

Anyway, there are some creatures on Earth that, while using the visible spectrum, also use part of the UV spectrum for vision. Various insects, for instance, can see into the UV spectrum - and some flowers have patterns on their petals that can only be seen in UV light to help attract the insects (to aid in pollination).

What would this mean for alien life? That they may be blind to most, if not all, of our "visible" spectrum, and we to theirs. This is not to say they would be blind, rather they would just find an inside room lit with light bulbs to be rather dim if not completely dark: most fluorescent lamps are designed to give off minimal amount of UV radiation - much less than what could be found out of doors (the mercury vapor in a fluorescent lamp does give off UV radiation, but it then collides with the phosphorus coating on the inside of the bulb, and thus is "converted" into visible light). Some lamps, like LEDs, do not give off any UV radiation. LEDs would be invisible to a being who sees only in the UV range.

This isn't an either/or proposition, of course. Some beings could have eyes sensitive to a large range, with part of their visible spectrum in the UV and part in our visible spectrum. They would be essentially color-blind in that they would see some colors, but not all (for instance, can only see blue and green). Many animals on Earth have limited color range, seeing mainly black and white. Even some humans only see in black and white: more than 5% of the natives of the island Ingelap, in Micronesia, have the rare condition of Monochromasy - total color blindness (Oliver Sacks wrote a book about them, titled The Island of the Colorblind).

Not sure how this would affect the alien's culture or theology, though they would see the night sky differently than we do, seeing patterns that we do not see, which could affect their theology to some degree. It would definitely affect their visual art - painting, drawing, and video. They would work on UV cameras first, and create UV TVs - rather different technology than what we came up with (I wonder how a UV TV would work?). The biggest affect, I believe, would be in the contact between us and them.

Of course, some Sci-Fi movies do have aliens that can only see in infrared or UV, though usually just in infrared, as it makes for more exciting drama to have an alien that can see our body heat - making us stand out like glaring targets, while the alien is concealed to our vision. That would indeed play on our visceral fears, if we knew that our new alien friends can readily see in infrared.

What other problems or difficulties can you think of?

Reference:

"Blackbody Radiation Exercises." Physics Dept., University of Tennessee, Knoxville. 23 November 2007. <http://csep10.phys.utk.edu/guidry/java/wien/wien.html>.

Habitable Zones

Barrie Jones, Emeritus Professor of Astronomy at The Open University in the UK, has devised a preliminary algorithm for determining the habitable zone (HZ) around a star. The HZ would vary depending upon the size of the system's star. More work needs to be done, for instance if the question needs to be raised that if

there giant planets too close to the habitable zone, so that an Earth-sized planet would be thrown out into interstellar space by the gravity of the giants?

Also, what would be the parameters of an HZ around a binary or trinary star systems? Right now, there is not enough data, nor enough computer modeling done, to answer those kinds of questions.



Reference:

"Modeling Other Earths." Astrobiology Magazine. 1 February 2007. 22 November 2007. <http://www.astrobio.net/news/article2225.html>.

Astronomers Map Out Planetary Danger Zone

Astronomers are beginning to refine areas in space where planets can form and survive and where they cannot. An important note in the article is that

"Stars move around all the time, so if one wanders into the danger zone and stays for too long, it will probably never be able to form planets," said Zoltan Balog of the University of Arizona, Tucson, lead author of the new report, appearing May 20 in the Astrophysical Journal ("Astronomers," Par. 3).

So, for a planet around a star in a nebula, small planets may be boiled away before they could finish forming. On planets that did form despite being in the nebula (not all areas of the nebula would be detrimental to planetary formation), life may have a bit of a struggle to hold on - and not only to hold on, but to be able to develop into sentient beings. If their star wanders into a "hot zone" in the nebula (too close to a super hot O type star), it will be blasted by dangerous solar winds and radiation that could, if it stayed too long, strip a planet of its atmosphere, or worst.

Some scientists think our sun was born in such an environment, but was able to keep its planets and move out into calmer regions of space.

Reference:

"Astronomers Map Out Planetary Danger Zone." Spitzer - NASA. 18 March 2006. 22 November 2007. <http://www.nasa.gov/mission_pages/spitzer/news/spitzer-20070418.html>.

The Sonnet Expands

The Universal Life Sonnet (see the Universal Biologies - Order from Chaos post below) expands - seems that scientist were too quick to discard the idea of life around a red giant. A red giant is the last phase of life for a normal G-type star (like our Sun). It is also its brightest stage. During this stage it will expand outward and devour the inner planets, or at the very least make uninhabitable (boiling away the oceans and atmosphere, for instance) including those in the habitable zone (HZ).

However, planets that were outside the original HZ may find themselves in the new HZ. Once frozen planets will warm up, and water will flow. For a few billion years, life will have a second chance. Life here on Earth took around 2.8 to 3.5 billion years or so to evolve to the point where we are today. If there was an advanced civilization on one of the inner planets, there is a rather good chance that they have at least sent probes to the outer planets, and contaminated them with microbial life (eukaryotic), giving life a kick start, shaving off billions of years of evolution (eukaryotic cell organisms developed 1.5 billion years ago - from the eukaryotic cells evolved multicellular life forms).

It's an interesting premise - what would life be like for a civilization rising up in the senior years of its star?

References:

NASA/Goddard Space Flight Center. "New Frontier Opens In The Search For Life On Other Planets." ScienceDaily 18 April 2005. 4 November 2007 .

Introduction

© Lynette Cook

The Blog's Focus
 

This blog focuses on extrasolar planetary discussions from scientific research to speculations on extrasolar (alien) biology, communication and linguistics, psychology, society, technology, and theology. This includes commentary on pertinent science articles, reviews of both relevant science and science fiction books and movies, and speculation that they inspire.

Why?

Why such discourses? As we move further into the 21rst century, these are topics will gain in importance as we continue to detect more exoplanets, to discover how widespread the building blocks of life are in the universe, and to expand the definition of life. The chances of our detecting life on another planet outside our solar system increase as our technology and techniques increase in sophistication (for example, the ability to analyze the atmosphere of a planet light years away).

Thus, the questions of whether life exists outside of the Earth take on new impetus. For with new life comes the possibility of new sentient life. What would that extrasolar sentient life be like? Pondering this question is not a mater of mere idle speculation. It goes beyond grown up fairy tales. Just as the examination of other planets in our solar system help us to understand our own planet, the examination of life on other planets may help us to understand ourselves. This meditation on other life affects meditation upon our own life.

As T.S. Eliot wrote in his poem "Little Gidding":

And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.

We need to explore, to learn.

Additionally, such contemplations can help us prepare for when we discover alien biologies, psychologies, societies, technologies and theologies.

Brief Background to the Issues

It seems that every few weeks there is another discovery of an exoplanet. As of October 2007 over 200 have been found. As more new telescopes, both on the ground and in space, having greater viewing power than the Hubble Space telescope come on line, the discoveries have not only begun to pick up speed, but ever smaller planets are being discovered as well.

In 2006 the ESA launched the COROT space telescope, designed to detect planets not much larger than the Earth. It began searching in Feb 2007 and has already found additional planets. In 2009 NASA plans to launch the Kepler space telescope, also designed to search for extrasolar planets. The James Webb Space Telescope, with a possible launch date of 2013, will be the replacement for Hubble, with greater observing powers than its predecessor. DARWIN, an European Space Agency proposed space telescope with a possible launch date of 2015, will be able to detect directly an earth sized extrasolar planet - with enough detail that we may even be able to determine if there is carbon-based life on it. In 2005, Dr. Webster Cash of the Univ of Colorado at Boulder, had his New Worlds Imager project funded by the NASA Institute for Advanced Concepts (NIAC). The project plans to build a large pinhole camera in Earth orbit capable of detecting Earth sized extrasolar planets up to 32 light years away. So far there is no proposed launch date. Even more extrasolar planet mission exist or are planned: for more information visit the Jet Propulsion Laboratory's "Planet Quest: Missions" page.

From a different angle, the newly powered up Allen Telescope Array, a SETI project, will increase the chances of detecting signals from extrasolar civilizations (those who have advanced to a technological level).

The next logical question, though, is how many extrasolar planets can harbor life? First, the building blocks of life, from simple chemicals like Carbon and water to more complex amino acids, are found throughout space in interstellar clouds, planetary disks, meteors and comets, and the atmosphere of exoplanets, as being expelled into space by dying stars. Some even theorize that is how life began on Earth - it was seeded from the heavens. Second, planets are being found (whole or forming) within the "habitable zones" of their parent stars (basically, the zone around a star where liquid water can exist) - a recent one is the fifth planet to be discovered around 55 Cancri.

Around the sun, the Habitable Zone is 0.95 to 1.37 A.U. However, life could possibly exist beyond this zone: scientists are now contemplating the possibility of life existing on Europa (there is a thin atmosphere of oxygen and quite possible a liquid ocean underneath the planet covering ice sheet). And finally, as we keep finding on Earth, life is tenacious - we are finding life everywhere on this planet, under an increasing range of conditions, including extreme conditions of no oxygen, boiling water, and frozen ice.

Because life can thrive under a wide range of conditions, it is most likely that alien life does not need a Earth duplicate on which to form and thrive, and thus it will be an astronomically minute chance that alien life will be duplicates of Earth life. There is a vast range of variables that can affect the direction alien biology takes, which in turn can affect the alien's psychology, society, technology, and theologies.

Closing Remarks

I don't want this blog to be one-sided. Please feel free to leave comments, whether to challenge or to support a speculation, or to suggest other references and resources. It is my hope this blog can be beneficial to its readers, including amateur philosophers, students looking for essay topics, and science fiction writers looking for ideas to stimulate writing, as well as for space science and/or science fiction fans.

© DigitalBlasphemy.com

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References:

"ATA." SETI Institute. 2007. Web. 30 October 2007. <http://www.seti.org/seti/projects/ata/>.

"Europa, a Continuing Story of Discovery." Project Galileo. NASA. Web. 30 October 2007. <http://www2.jpl.nasa.gov/galileo/europa/>.

"Extrasolar planet." Wikipedia, The Free Encyclopedia. 4 Nov 2007, 07:02 UTC. Wikimedia Foundation, Inc. Web. 4 Nov 2007. <http://en.wikipedia.org/w/index.php?title=Extrasolar_planet&oldid=169111401>.

Jet Propulsion Laboratory. "Planet Quest: Missions." NASA. Web. 30 October 2007. <http://planetquest.jpl.nasa.gov/missions/missions_index.cfm>.

Johns Hopkins University. "Earth-like Planet Forming In Nearby Star System, Astronomers Believe." ScienceDaily. 4 October 2007. Web. 30 October 2007. <http://www.sciencedaily.com/releases/2007/10/071003130744.htm>.

NASA Goddard Space Flight Center. "Cornucopia Of Earth-sized Planets Modeled By NASA." ScienceDaily. 25 September 2007. 30 October 2007. <http://www.sciencedaily.com­/releases/2007/09/070924132510.htm>.

NASA/Marshall Space Flight Center. "NASA Scientist Discovers New Species Of Organism In Mars-like Environment." ScienceDaily. 31 July 2003. Web. 30 October 2007 <http://www.sciencedaily.com/releases/2003/07/030731081613.htm>.

"Notes for star 55 Cnr [55 Cancri]" Extrasolar Planets Encyclopedia. Web. 4 November 2007. <http://exoplanet.eu/star.php?st=55+Cnc>.

University of California, Los Angeles. "Polluted Dead Star Indicates Planets Like Earth May Have Formed Around Other Stars." ScienceDaily. 17 August 2007. Web. 30 October 2007 <http://www.sciencedaily.com/releases/2007/08/070816214820.htm>.

University of Liège. "Astronomers Detect Shadow Of Water World In Front Of Nearby Star." ScienceDaily 16 May 2007. Web. 30. October 2007 <http://www.sciencedaily.com­/releases/2007/05/070516151053.htm>.