Wednesday, January 9, 2008
Methuselah - Addendum
The Methuselah - 13 Billion Yr Old Planet (Garden of Eden?) post has been updated, thanks to a reader's feedback who correctly pointed out that I mislabeled M4 as an open cluster. I also addressed the issue of the low metallic nature of early globular clusters more clearly - early stellar nurseries should not be capable of producing planets, yet here we have at least one that was formed 13 billion years ago. The probability of life forming on that planet is rather low (at least life as we know it) as it is most likely a gaseous planet, but not zero. And it does raise the possibility (this blog is about speculation, after all) that other ancient planets exist - including a smaller terrestrial planet orbiting in the same system as Methuselah which current methods do not allow us to detect. And that raises the possibility, even if a slim one, that life did arise far earlier in the universe than first thought.
Saturday, January 5, 2008
Methuselah - 13 Billion Yr Old Planet (Garden of Eden?)
In 2003, astronomers using the Hubble Space Telescope discovered something amazing deep in the M4 globular cluster 7,200 light years away - something that shouldn't be: a planet, 2.5 times the size of Jupiter, orbiting 23 AUs from a pulsar (a rotating, pulsating neutron star), PSR B1620-26. The primary star, the pulsar, has a companion white dwarf orbiting approx 1 AU out.
According to current theories, planets could not form in the early universe (1) - for one thing, early stellar nurseries shouldn't have enough heavy elements to create stars with planets. But somehow at least one planet was formed in the young universe - while the universe is 14 to 15 billion years old, this planet, dubbed Methuselah, is nearly 13 billion years old.
Imagine that - a planet almost as old as the universe itself. Could a civilization have arisen there? Or died out and rose again (that old of a planet, life would have time to restart several times)? And in the final years, moved out into the stars?
I can't help but think of old races often called "The Ancients" or similar such nomenclature in science fiction tales - very old races that seed the rest of the galaxy before ascending or mysteriously moving on to other galaxies, leaving this one behind.
And if life first began in this universe on such an old planet (or, more likely, a smaller sister planet), could that then be the real Garden of Eden, from which Adam and Eve where exiled from?
Of course, orbiting a pulsar is dangerous for life for two reasons: 1) a pulsar is a result of a supernova which tends to destroy worlds (strip away the atmospheres at the very least) and 2) pulsars give off extremely intense beams of radiation along the lines of its magnetic axis - if any planet is in the path of the beam of the rapidly spinning star, the radiation would be too intense for life to survive or form (2).
As we have seen in a previous post, Planets, planets everywhere, planets can reform around a pulsar - from the rocky debris of the original planets, blasted from the supernova explosion.
Scientists, however, do not feel that Methuselah is a "reconstituted" planet. One theory is that the planet (and maybe others too small to be detected by present means) was captured from a sideswipe with another younger system later on - a system that existed for 10 billion years before wandering too deep into the core of the globular cluster, where distances between star systems can sometimes be less than 1 light year.
Recall from an earlier post, An Aside - Are There Alien Worlds in Our Own Solar System?, there is some evidence that our own solar system has "adopted" objects from an alien solar system passing by in the distant past - possibly when it was still in an open globular cluster (scientists theorize that our sun was first formed in an open cluster).
In fact, the scientists feel that the white dwarf companion was also "adopted" by the primary neutron star. They theorize that the pulsar did have a dwarf companion at first, but when a yellow star system came too close, the gravitational tug-of-war kicked out the dwarf and the yellow star took its place, along with at least one of its planets. The new system then moved out from the core of the globular cluster - reducing any chances for further collisions.
In this new binary system, some of the mass from the yellow star got sucked into the pulsar, speeding up its rotation, giving it the incredible spin rate of 100 revolutions every second. After some millions of years, the yellow star became a red giant and then a white dwarf.
So it is quite possible that the Methuselah, and any other world(s) circling PSR B1620-26, were "adopted," right along with their sun. If so, could one of them developed life before being captured by the pulsar/dwarf system? Early planetary systems would most likely be made up of gaseous planets - there shouldn't be enough heavy elements for terrestrial planets to form. But then we didn't think any planets as old as Methuselah should exist either. Maybe, just maybe, a small terrestrial planet does exist along with Methuselah. And even if not, life is not necessarily restricted to terrestrial planets - life could begin and thrive on non-terrestrial planets (albeit, such life would not be life as we know it).
One problem such life would face is that being captured by the pulsar would prove to be quite the dramatic change. If they are lucky, the radiation beam from the pulsar would point far above the ecliptic, thus avoiding being bathed in intense radiation every 1/100th of a second; but even then, the difference in light (and heat) would be devastating as it is rather certain the planets' new orbits around the binary pair would be different than when they were just circling around their single parent star. But as we see on Earth, life, once formed, is tenacious and will find a way to survive, even during the occasional mass extinctions.
For intelligent life, depending upon their level of technological advancement, they could migrate to a sister world circling the new binary system, one that was now more hospitable than their home world. Otherwise, they would be forced to adapt to their new, darker, colder world. Or, if they were highly advanced at the time the collision was imminent, and finding themselves in a crowded neighborhood, could explore nearby systems and move to one that was safer -though it is doubtful any planetary system in the core of cluster would be safer, especially any system that was lingering in the core, and thus increased chances of itself colliding with another star system. No, more likely they would have to figure out how best to ride out the collision.
At first scientists thought planetary systems couldn't survive long in a cluster, especially a globular cluster - but increasing evidence is showing that sometimes this is not the case. Although, lingering too long in a cluster is still thought not the best environment for life; for one thing, a globular cluster has many stars in relatively close proximity - a supernova from a nearby star can have devastating effects for life on the planets of neighboring star systems and being in a globular cluster, chances for being near a supernova are rather high. For the Earth, a supernova 30 light years or closer would be quite devastating for life - for other planets, the distance could be greater, depending upon how thick their protective atmospheres are (to show you how protective our atmosphere is, for astronauts outside the Earth's atmosphere, a supernova 3,000 light years away could be deadly).
But, it is not impossible. That extrasolar system could have been one of the earliest gardens of life in the universe. 12.7 billion years ago the planetary system was formed. Our own system is "merely" 4.5 billion years. It is thought that the first 10 billion years Methuselah led a "normal" life around a normal sun like star. And if it was, was that life able to evolve to a space faring species? Are there descendants scattered about the Milky Way (or at least in that region of the Milky Way)?
Notes:
1. Early stars were poor in heavy elements, and thus could not form planets, but when they died, they produced heavy elements which then became part of new nebulae within which new stars were born - and with heavy elements now in the mix, allowing planets to finally be formed as well.
2. While pulsars are formed from massive stars, white dwarfs are formed from the average main sequence star - most stars in the galaxy will end their lives as white dwarves.
References:
Britt, Robert Roy. "Primeval Planet: Oldest Known World Conjures Prospect of Ancient Life." Science. SPACE.com. 10 July 2003. 6 January 2008. <http://www.space.com/scienceastronomy/oldest_planet_030710-1.html>
"Extrasolar Visions - 'Methuselah' PSR B1620-26 c." Extrasolar Planet Guide. 5 January 2008. <http://www.extrasolar.net/planettour.asp?PlanetID=30>
"Messier Object 4." The Messier Catalog. SEDS. 21 August 2007. 6 January 2008. <http://www.seds.org/Messier/M/m004.html>
Mukai, Koji and Eric Christian. "Destruction of the Earth by a Nearby Supernova." Ask an Astrophysicist. Imagine the Universe! 1 December 2005. 5 January 2008. <http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980521a.html>
"Oldest Planet Challenges Existing Theories." This Week in Science. 11 July 2003. 5 January 2008. <http://www.twis.org/2003_07_11_science_news.html>
Richmond, Michael. "Will a Nearby Supernova Endanger Life on Earth?" 8 April 2005. 5 January 2008. <http://stupendous.rit.edu/richmond/answers/snrisks.txt>
According to current theories, planets could not form in the early universe (1) - for one thing, early stellar nurseries shouldn't have enough heavy elements to create stars with planets. But somehow at least one planet was formed in the young universe - while the universe is 14 to 15 billion years old, this planet, dubbed Methuselah, is nearly 13 billion years old.
Imagine that - a planet almost as old as the universe itself. Could a civilization have arisen there? Or died out and rose again (that old of a planet, life would have time to restart several times)? And in the final years, moved out into the stars?
I can't help but think of old races often called "The Ancients" or similar such nomenclature in science fiction tales - very old races that seed the rest of the galaxy before ascending or mysteriously moving on to other galaxies, leaving this one behind.
And if life first began in this universe on such an old planet (or, more likely, a smaller sister planet), could that then be the real Garden of Eden, from which Adam and Eve where exiled from?
Of course, orbiting a pulsar is dangerous for life for two reasons: 1) a pulsar is a result of a supernova which tends to destroy worlds (strip away the atmospheres at the very least) and 2) pulsars give off extremely intense beams of radiation along the lines of its magnetic axis - if any planet is in the path of the beam of the rapidly spinning star, the radiation would be too intense for life to survive or form (2).
As we have seen in a previous post, Planets, planets everywhere, planets can reform around a pulsar - from the rocky debris of the original planets, blasted from the supernova explosion.
Scientists, however, do not feel that Methuselah is a "reconstituted" planet. One theory is that the planet (and maybe others too small to be detected by present means) was captured from a sideswipe with another younger system later on - a system that existed for 10 billion years before wandering too deep into the core of the globular cluster, where distances between star systems can sometimes be less than 1 light year.
Recall from an earlier post, An Aside - Are There Alien Worlds in Our Own Solar System?, there is some evidence that our own solar system has "adopted" objects from an alien solar system passing by in the distant past - possibly when it was still in an open globular cluster (scientists theorize that our sun was first formed in an open cluster).
In fact, the scientists feel that the white dwarf companion was also "adopted" by the primary neutron star. They theorize that the pulsar did have a dwarf companion at first, but when a yellow star system came too close, the gravitational tug-of-war kicked out the dwarf and the yellow star took its place, along with at least one of its planets. The new system then moved out from the core of the globular cluster - reducing any chances for further collisions.
In this new binary system, some of the mass from the yellow star got sucked into the pulsar, speeding up its rotation, giving it the incredible spin rate of 100 revolutions every second. After some millions of years, the yellow star became a red giant and then a white dwarf.
So it is quite possible that the Methuselah, and any other world(s) circling PSR B1620-26, were "adopted," right along with their sun. If so, could one of them developed life before being captured by the pulsar/dwarf system? Early planetary systems would most likely be made up of gaseous planets - there shouldn't be enough heavy elements for terrestrial planets to form. But then we didn't think any planets as old as Methuselah should exist either. Maybe, just maybe, a small terrestrial planet does exist along with Methuselah. And even if not, life is not necessarily restricted to terrestrial planets - life could begin and thrive on non-terrestrial planets (albeit, such life would not be life as we know it).
One problem such life would face is that being captured by the pulsar would prove to be quite the dramatic change. If they are lucky, the radiation beam from the pulsar would point far above the ecliptic, thus avoiding being bathed in intense radiation every 1/100th of a second; but even then, the difference in light (and heat) would be devastating as it is rather certain the planets' new orbits around the binary pair would be different than when they were just circling around their single parent star. But as we see on Earth, life, once formed, is tenacious and will find a way to survive, even during the occasional mass extinctions.
For intelligent life, depending upon their level of technological advancement, they could migrate to a sister world circling the new binary system, one that was now more hospitable than their home world. Otherwise, they would be forced to adapt to their new, darker, colder world. Or, if they were highly advanced at the time the collision was imminent, and finding themselves in a crowded neighborhood, could explore nearby systems and move to one that was safer -though it is doubtful any planetary system in the core of cluster would be safer, especially any system that was lingering in the core, and thus increased chances of itself colliding with another star system. No, more likely they would have to figure out how best to ride out the collision.
At first scientists thought planetary systems couldn't survive long in a cluster, especially a globular cluster - but increasing evidence is showing that sometimes this is not the case. Although, lingering too long in a cluster is still thought not the best environment for life; for one thing, a globular cluster has many stars in relatively close proximity - a supernova from a nearby star can have devastating effects for life on the planets of neighboring star systems and being in a globular cluster, chances for being near a supernova are rather high. For the Earth, a supernova 30 light years or closer would be quite devastating for life - for other planets, the distance could be greater, depending upon how thick their protective atmospheres are (to show you how protective our atmosphere is, for astronauts outside the Earth's atmosphere, a supernova 3,000 light years away could be deadly).
But, it is not impossible. That extrasolar system could have been one of the earliest gardens of life in the universe. 12.7 billion years ago the planetary system was formed. Our own system is "merely" 4.5 billion years. It is thought that the first 10 billion years Methuselah led a "normal" life around a normal sun like star. And if it was, was that life able to evolve to a space faring species? Are there descendants scattered about the Milky Way (or at least in that region of the Milky Way)?
Notes:
1. Early stars were poor in heavy elements, and thus could not form planets, but when they died, they produced heavy elements which then became part of new nebulae within which new stars were born - and with heavy elements now in the mix, allowing planets to finally be formed as well.
2. While pulsars are formed from massive stars, white dwarfs are formed from the average main sequence star - most stars in the galaxy will end their lives as white dwarves.
References:
Britt, Robert Roy. "Primeval Planet: Oldest Known World Conjures Prospect of Ancient Life." Science. SPACE.com. 10 July 2003. 6 January 2008. <http://www.space.com/scienceastronomy/oldest_planet_030710-1.html>
"Extrasolar Visions - 'Methuselah' PSR B1620-26 c." Extrasolar Planet Guide. 5 January 2008. <http://www.extrasolar.net/planettour.asp?PlanetID=30>
"Messier Object 4." The Messier Catalog. SEDS. 21 August 2007. 6 January 2008. <http://www.seds.org/Messier/M/m004.html>
Mukai, Koji and Eric Christian. "Destruction of the Earth by a Nearby Supernova." Ask an Astrophysicist. Imagine the Universe! 1 December 2005. 5 January 2008. <http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980521a.html>
"Oldest Planet Challenges Existing Theories." This Week in Science. 11 July 2003. 5 January 2008. <http://www.twis.org/2003_07_11_science_news.html>
Richmond, Michael. "Will a Nearby Supernova Endanger Life on Earth?" 8 April 2005. 5 January 2008. <http://stupendous.rit.edu/richmond/answers/snrisks.txt>
Links Updated
The Exoplanet Links have been updated: not only have I added more links, but I have also divided the Astrobiology links from the Exoplanet Links, giving each their own section.
Saturday, December 22, 2007
Terrestrial Planets Forming in the Subaru!
© Lynette R. Cook, for Gemini Observatory.
"This is the first clear evidence for planet formation in the Pleiades, and the results we are presenting may well be the first observational evidence that terrestrial planets like those in our solar system are quite common," said Joseph Rhee, a UCLA postdoctoral scholar in astronomy and lead author of the research (UCLA, par. 3).The Pleiades is a young open cluster 400 light years away. Some scientists feel that our Sun was formed in an open cluster as well; stars in an open cluster tend to wander from the "nest" as they age. So, we may see the beginnings of home worlds for future Subaruians (Pleiadians?).
Reference:
UCLA News Results. "Planets found forming in Pleiades star cluster." SpaceFlight Now. 15 November 2007. 22 December 2007. <http://spaceflightnow.com/news/n0711/15pleiades/>
Thursday, December 20, 2007
Christmas on Omicron Persei 8
During this time of year, my thoughts turn philosophically, sentimentally deeper toward several things: family, the past, spirituality and, of course, life on other planets.
For family, this time of year means additional sentimental thoughts partly because, for the Northern hemisphere, the weather is growing colder, and the nights darker and longer, and so our hearts instinctively look to shorten the distances between loved ones to increase warmth, security, and hope.
For the past, at this time of year, with the New Year approaching, it is a time that we begin to realize that another year has gone, and we begin to look back and take stock of what has happened - sometimes with happiness, sometimes with new knowledge realized, sometimes with anger, sometimes with regret, and sometimes with sadness. If used right, it is a time of extra growth.
For spirituality, this season has strong, and many times somewhat similar, religious meanings for many of the world's theologies. This is in large part because, again for the Northern hemisphere, the Winter solstice brings not only the longest night of the year, but the knowledge that the days will now begin to lengthen again - the Sun returns, and with it renewed warmth and energy filled life. It is the promise of Spring. It is the promise of rebirth, renewal, and resurrection that we rejoice in and are thankful for. It is the promise of death conquered. And connected with looking back to the year that was, and looking close to loved ones, it is a time of year to be thankful yet again for the blessings that loved ones, that love, brings (though for those struggling with a bad year, with abandonment, it can be a very dark time of year indeed).
Of course, too often all of this is ruined by crass commercialism, by the pressures and stresses of false and shallow meanings that have been attached to the season. But that is a topic for other blogs.
For life on other planets, I wonder how they would treat a solstice on their planet? To be high level sentient does one have to be a pattern seeker, to look for the meaning and/or reasons for the patterns? If so, then such sentient beings would see the pattern of solstice and equinox as even our distant ancestors did (from even before Stonehenge) and work to apply a meaning or reason to the pattern (for to find meaning or reason is to find purpose and to be able to make predictions, and maybe even gain some control over - or at least the illusion/delusion of some control).
This, of course, depends on many factors which would affect the severity, or the placidness, of annual weather patterns. Is the planet in a very circular orbit, or a somewhat elliptical one? Is the planet close to its star, and thus with a very short year? Is the planet actually a large habitable moon circling a gas giant? Is there a virtually non-existent tilt to its axis or it is a large tilt? And what of these combined?
If, for instance, the planet is in a very circular orbit, at a close orbit (a red dwarf, for instance, would have a habitable zone much closer to it than a normal G-type star like our own Sun), and with virtually no tilt to its axis, such a planet may have very little differences between its seasons - and seasons that come and go quickly (smaller orbit means, usually, a shorter year). If a longest night is very quickly followed by a longest day (weeks later, i.e.), would there be as much imperative to celebrate the return of the sun's dominance in the sky?
For a planet-moon circling a gas giant, the sun could disappear for days at a time before returning to a "regular" schedule.
Or if the planet-moon is phase locked with its parent gas giant planet, then for the time it is behind the planet there would be, for the far side of the planet-moon there would be constant darkness until the planet-moon came out from behind the gas giant; but then the sun would rise and stay in the sky as it slowly arcs to the opposite horizon as the planet-moon orbits in front of the gas giant. On such a world, a short winter may cover the entire globe while in the shadow of the gas giant, and summer cover the entire globe while in front of the gas giant with extremely short springs and fall at the point the planet-moon is over the terminator line of the gas giant (the line where day and night on the gas giant meet, where one begins and the other ends). Maybe the world's sentient race would view their world as more of a unity than we view our own as on Earth the Northern and Southern hemispheres experience direct opposite seasons at the same time, while on this hypothetical world, both hemispheres experience the same season at the same time.
Anyway, back to the long day and long night, a primitive sentient mind may see that as a mighty heroic epic struggle between day and night. Though if a non-aggressive sentient species, say a slow moving herbivore species on a cool planet, maybe the day and night would represent a sort of "wheel of fortune" - first good luck (sun, warmth, plants taking full advantage) and then bad luck (days long darkness, worsening cold, plants folding up waiting for the sun)?
Additionally, there would be no solstice like we have - there would be no gradual shortening of the night - just one long night, and then one long day, each individual night as long as the night before, separated by an equally long day. Essentially, they would be in eternal equinox. Spring would be morning, summer would be the day, fall would be the evening, and winter would be the night - if you wanted to give them seasons. It may be more accurate to say such a world would have no real seasons at all, only the kind of "seasons" any day-night cycle would have.
If, instead, the planet-moon did have a noticeable tilt to its axis, and a non-circular orbit around its parent gas giant planet, which itself had a non-circular orbit around the central sun, or if the parent planet had a noticeable tilt to its axis with the planet-moon orbiting directly over the parent planet's equator, then the planet-moon, while still retaining non-changing lengths to its day and nights, would gain true seasons. The sun would arc over the sky differently through out the parent planet's year - while the planet-moon's year is the time it takes to orbit around the gas giant, the gas giant has its own year as it orbits its sun.
On such a world, a season would not be different parts of the planet-moon's year, but would be seen year to year. A number of years would be Spring, while another number of years would be Summer, and so forth, repeating itself. What a different kind of zodiac such a world would have! In some ways, it would be similar to a Chinese zodiac calendar (the year of the horse, the year of the dog, etc), except each zodiac would cover a span of years. Their zodiac could contain a zodiac within a zodiac within a zodiac.
Solstice on such a world may not represent so much the return of day, since it is possible that the day and nights would not change in length from year to year, but could represent the point where Winter is half over and thus the return of Spring begins. And maybe, just maybe, the celebration would be a whole year (for the planet-moon).
Of course, this is supposing that all higher level sentient beings feel, in an emotive sense, for in some ways spirituality, and especially sentimentality, depends upon emotion more (at least at times) than reason. Is emotion necessary to higher level of sentience? It seems on Earth, at least, the higher the level of sentience, the more emotion the creature seems to have.
But this is a topic for a future blog.
Comments? Feel free to comment on any post in this blog. Please feel free to disagree with me (just do so respectfully please - even if you think I sin in any or all of my opinions, please recall, if you are Christian, Jesus' attitude toward the adulteress: while he was against what she did, he did not condemn her, and turned away those who would stone her).
Happy Holidays to you and yours (and even to Lrrr, Ruler of Omicron Persei 8, and his wife Nd-Nd. And what the heck, to Robot Santa too!*).
* If Lrrr, Nd-Nd, and Robot Santa mean nothing to you, you need to run, not walk, to the TV and catch an episode of Futurama.
For family, this time of year means additional sentimental thoughts partly because, for the Northern hemisphere, the weather is growing colder, and the nights darker and longer, and so our hearts instinctively look to shorten the distances between loved ones to increase warmth, security, and hope.
For the past, at this time of year, with the New Year approaching, it is a time that we begin to realize that another year has gone, and we begin to look back and take stock of what has happened - sometimes with happiness, sometimes with new knowledge realized, sometimes with anger, sometimes with regret, and sometimes with sadness. If used right, it is a time of extra growth.
For spirituality, this season has strong, and many times somewhat similar, religious meanings for many of the world's theologies. This is in large part because, again for the Northern hemisphere, the Winter solstice brings not only the longest night of the year, but the knowledge that the days will now begin to lengthen again - the Sun returns, and with it renewed warmth and energy filled life. It is the promise of Spring. It is the promise of rebirth, renewal, and resurrection that we rejoice in and are thankful for. It is the promise of death conquered. And connected with looking back to the year that was, and looking close to loved ones, it is a time of year to be thankful yet again for the blessings that loved ones, that love, brings (though for those struggling with a bad year, with abandonment, it can be a very dark time of year indeed).
Of course, too often all of this is ruined by crass commercialism, by the pressures and stresses of false and shallow meanings that have been attached to the season. But that is a topic for other blogs.
For life on other planets, I wonder how they would treat a solstice on their planet? To be high level sentient does one have to be a pattern seeker, to look for the meaning and/or reasons for the patterns? If so, then such sentient beings would see the pattern of solstice and equinox as even our distant ancestors did (from even before Stonehenge) and work to apply a meaning or reason to the pattern (for to find meaning or reason is to find purpose and to be able to make predictions, and maybe even gain some control over - or at least the illusion/delusion of some control).
This, of course, depends on many factors which would affect the severity, or the placidness, of annual weather patterns. Is the planet in a very circular orbit, or a somewhat elliptical one? Is the planet close to its star, and thus with a very short year? Is the planet actually a large habitable moon circling a gas giant? Is there a virtually non-existent tilt to its axis or it is a large tilt? And what of these combined?
If, for instance, the planet is in a very circular orbit, at a close orbit (a red dwarf, for instance, would have a habitable zone much closer to it than a normal G-type star like our own Sun), and with virtually no tilt to its axis, such a planet may have very little differences between its seasons - and seasons that come and go quickly (smaller orbit means, usually, a shorter year). If a longest night is very quickly followed by a longest day (weeks later, i.e.), would there be as much imperative to celebrate the return of the sun's dominance in the sky?
For a planet-moon circling a gas giant, the sun could disappear for days at a time before returning to a "regular" schedule.
Or if the planet-moon is phase locked with its parent gas giant planet, then for the time it is behind the planet there would be, for the far side of the planet-moon there would be constant darkness until the planet-moon came out from behind the gas giant; but then the sun would rise and stay in the sky as it slowly arcs to the opposite horizon as the planet-moon orbits in front of the gas giant. On such a world, a short winter may cover the entire globe while in the shadow of the gas giant, and summer cover the entire globe while in front of the gas giant with extremely short springs and fall at the point the planet-moon is over the terminator line of the gas giant (the line where day and night on the gas giant meet, where one begins and the other ends). Maybe the world's sentient race would view their world as more of a unity than we view our own as on Earth the Northern and Southern hemispheres experience direct opposite seasons at the same time, while on this hypothetical world, both hemispheres experience the same season at the same time.
Anyway, back to the long day and long night, a primitive sentient mind may see that as a mighty heroic epic struggle between day and night. Though if a non-aggressive sentient species, say a slow moving herbivore species on a cool planet, maybe the day and night would represent a sort of "wheel of fortune" - first good luck (sun, warmth, plants taking full advantage) and then bad luck (days long darkness, worsening cold, plants folding up waiting for the sun)?
Additionally, there would be no solstice like we have - there would be no gradual shortening of the night - just one long night, and then one long day, each individual night as long as the night before, separated by an equally long day. Essentially, they would be in eternal equinox. Spring would be morning, summer would be the day, fall would be the evening, and winter would be the night - if you wanted to give them seasons. It may be more accurate to say such a world would have no real seasons at all, only the kind of "seasons" any day-night cycle would have.
If, instead, the planet-moon did have a noticeable tilt to its axis, and a non-circular orbit around its parent gas giant planet, which itself had a non-circular orbit around the central sun, or if the parent planet had a noticeable tilt to its axis with the planet-moon orbiting directly over the parent planet's equator, then the planet-moon, while still retaining non-changing lengths to its day and nights, would gain true seasons. The sun would arc over the sky differently through out the parent planet's year - while the planet-moon's year is the time it takes to orbit around the gas giant, the gas giant has its own year as it orbits its sun.
On such a world, a season would not be different parts of the planet-moon's year, but would be seen year to year. A number of years would be Spring, while another number of years would be Summer, and so forth, repeating itself. What a different kind of zodiac such a world would have! In some ways, it would be similar to a Chinese zodiac calendar (the year of the horse, the year of the dog, etc), except each zodiac would cover a span of years. Their zodiac could contain a zodiac within a zodiac within a zodiac.
Solstice on such a world may not represent so much the return of day, since it is possible that the day and nights would not change in length from year to year, but could represent the point where Winter is half over and thus the return of Spring begins. And maybe, just maybe, the celebration would be a whole year (for the planet-moon).
Of course, this is supposing that all higher level sentient beings feel, in an emotive sense, for in some ways spirituality, and especially sentimentality, depends upon emotion more (at least at times) than reason. Is emotion necessary to higher level of sentience? It seems on Earth, at least, the higher the level of sentience, the more emotion the creature seems to have.
But this is a topic for a future blog.
Comments? Feel free to comment on any post in this blog. Please feel free to disagree with me (just do so respectfully please - even if you think I sin in any or all of my opinions, please recall, if you are Christian, Jesus' attitude toward the adulteress: while he was against what she did, he did not condemn her, and turned away those who would stone her).
Happy Holidays to you and yours (and even to Lrrr, Ruler of Omicron Persei 8, and his wife Nd-Nd. And what the heck, to Robot Santa too!*).
* If Lrrr, Nd-Nd, and Robot Santa mean nothing to you, you need to run, not walk, to the TV and catch an episode of Futurama.
Wednesday, December 19, 2007
Hazy red sunset on an extrasolar planet...
© NASA, ESA, & G. Bacon (STScI)
The exciting aspect of this is, of course, the increased possibility that astronomers may, within years, measure the atmosphere of a planet that bears life - and life will leave its mark on any atmosphere. While not cold, hard, definitive proof of life (even then, some folk would just refuse to accept), it would be exciting evidence.A team of astronomers have used the NASA/ESA Hubble Space Telescope to detect, for the first time, strong evidence of hazes in the atmosphere of a planet orbiting a distant star. The discovery comes after extensive observations made recently with Hubble's Advanced Camera for Surveys (ACS).
The team, led by Frederic Pont from the Geneva University Observatory in Switzerland, used Hubble's ACS to make the first detection of hazes in the atmosphere of the giant planet. "One of the long-term goals of studying extrasolar planets is to measure the atmosphere of an Earth-like planet, this present result is a step in this direction" says Pont. "HD 189733b is the first extrasolar planet for which we are piecing together a complete idea of what it really looks like."
For a "Hubblecast" video of this new find, and more info on "hot Jupiters," visit <http://www.spacetelescope.org/videos/vodcast/heic0720a.m4v>
Reference:
"Hazy Red Sunset on Extrasolar Planet." SpaceRef. com. 11 December 2007. 19 December 2007. <http://www.spaceref.com/news/viewpr.html?pid=24244>
"Heic0720: Hazy Red Sunset on Extrasolar Planet." News and Photo Releases. The European Homepage for the NASA/ESA Hubble Space Telescope. <http://www.spacetelescope.org/news/html/heic0720.html>
Sunday, December 16, 2007
Alien Safari!
© NASA, JPL
The Safari includes the weird methane-ice worms found deep 80 miles off the coast of Louisiana. Life finds a way yet again! Though, to be fair, this doesn't necessarily mean that life can originate everywhere, just that life, once established, is tenacious and difficult to get rid of (you can, unfortunately, eliminate individual species easily, but getting rid of life entirely is extremely difficult). So it may bode well for terraformers more than for those searching for alien life. However, I still bet on life being rather common in solar systems.
Alien Safari destinations:
- Living Without Sunlight
- Highest Radiation Dose
- Most Acidic
- Farthest Underground
- Strangest Habitat
- Hottest
"Alien Safari." Planet Quest. Jet Propulsion Laboratory. 16 December 2007. <http://planetquest.jpl.nasa.gov/AlienSafari_launch_page.html>
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