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Posted on 03/31/2005 4:27:51 PM PST by Heartlander
Five Out of Five Researchers Agree: Earth's Solar System Special
By Sara Goudarzi
Special to SPACE.com
posted: 31 March 2005
NEW YORK -- Though researchers find more and more distant planets revolving around alien suns, the discoveries highlight that Earth and its solar system may be an exceptionally rare place indeed.
That was the consensus here Wednesday evening among five planetary science experts who spoke at the 5th annual Isaac Asimov Memorial Panel Debate held at the American Museum of Natural History.
Neil DeGrasse Tyson, the Frederick P. Rose Director of the Hayden Planetarium, moderated the informal discussion. At issue was whether our solar system is special, why it looks the way it does, and how others thus far detected differ. The debate took place between theoretical and observational scientists on the different aspects of detecting and categorizing alien solar systems. About 700 people attended the event.
Prior to the discovery of planets around stars other than our sun in the 1990’s, scientists thought that alien solar systems must look something like our own. They presumed that just like our solar system, there would be small rocky planets like as Earth close to their host stars and large, low density ones a little farther out. But what they discovered were solar systems unlike ours with big Jupiter-like planets close to their host star.
Of the 150 alien planets found, none of them resemble our own. “So maybe it’s not the enigma of other solar systems, it’s the enigma of our solar system,” Tyson said in opening the debate.
The trouble with understanding planets outside of our solar system is that they are typically hard to see because of their bright host star, explained Paul Butler, co-discoverer of two-thirds of the known extra solar planets. However, even with these constraints, indirect methods allowed scientists to detect planets as massive as 300 times the Earth and ones as small as 15 times the mass of the Earth outside of our solar system,
As it turns out, the mass of a planet is its most important characteristic for comparative astrometry, the measurement of star positions. The mass determines if a planet is a gas giant or a rocky formation. “If it’s a rocky planet, like Earth or Mars, then one can focus on its atmosphere and learn more about its characteristics,” said Fritz Benedict of the University of Texas.
Typically, the most sought after characteristic of a planet is its habitability. A habitable planet has liquid water on its surface, explained Margaret Turnbull of the Carnegie Institute of Washington. Thus far, 90% of all detected alien planets have host stars that can flare and sterilize the surface of the planet. Furthermore, planets, which are that close to their host star, would be in a synchronous orbit. This means that only one side of the planet would face the host star and all potential water on that side would evaporate and go to its “dark” side.
While theorists such as Peter Goldrich of Caltech and Scott Termain of Princeton University did not predict finding solar systems with Jupiter-like planets so close to their orbit stars, they did theorize their dynamics. As early as the1980’s, they showed that planets such as Jupiter could be very mobile, moving rapidly, and changing angle and momentum to switch orbits and migrate closer to their parent stars. “Planetary system is not static, it’s continually processing. Orbits jiggle around,” said Termain.
At the end, all agreed that there are still discoveries to be made before we can know if our solar system is special or unusual amongst the universe. But speculations varied.
“I have a problem referring to our own solar system as unusual, because we haven’t done that experiment yet, we haven’t searched for our own solar system yet,” said Turnbull Thus far, the kind of data obtained and the type of observations made are tuned to search for Jupiters and not Earths, therefore that’s what we find. “The experiments were designed for that,” she explained.
But with the vast majority of the alien planets found in eccentric orbits, Butler has a different view. “I think with the data at hand, we can say that our solar system is rare. Eccentricity dominates,” said Butler. “It’s just a matter of how rare we are,” he added.
And Benedict agrees. “The older I get, the less likely it seems to me there’d be a bunch of places like our solar system,” he said. Or as Tyson added, “There’s no place like home.”
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I agree. I'd make this argument:
1. Physically, it takes the entire universe just to support the one life-planet we already know of (see my post above).
2. Biblically, Jesus died "once for all." If God created already, or creates in the future, another set of spirit-beings (besides us and the angels), presumably they would fall, also. Would a person of the Godhead (could there be more than three?) die again? I say "presumably" because God, being God, is not bound by my finite idea of how He might create.
3. Economically, why should He bother creating elsewhere/when? Isn't the fantastic period still ahead, for Him and the angels and us? The God who created 100 billion galaxies, each with 100 billion stars, and has kept them running 14 billion years, is capable of an eternity's worth of creative delight for us.
OMG. Our solar system is riding the short bus.
We'll probably never know either way in our lifetimes, but it's fun to speculate.
Thanks for the link--I'll check it out.
special ping!
Thanks. I've seen many planetary systems. This one is ... well, I'd judge it so-so.
I've been reading down the list on the first link at that webpage and I just wanted to mention that much of that is pure nonsense. There's just way too much there to bother dealing with, but figured you should know. I actually started drafting a reply, but gave up after the first four items alone took so long.
"If earth were just 1% closer to or farther from the sun, the water cycle would break down and life would not exist on earth.
* If earth's mass (i.e., its gravity) were 2% larger or smaller, life would not exist on earth. "
These examples assume that life needs water, clouds and the escape of methane. They also assume there is no other way for these parameters to be satisfied.
Imperialists!
Spot on analogy.
Perhaps I will sleep better tonight, but the problem is that I tend to leave posts on more thean one thread.
Suit yourself. I'd merely suggest that a more extensive survey than your brief one would be rewarding for you.
You are, of course, absolutely correct. Many of the more than 200 examples on the website I referred to (reasons.org) make similar assumptions.
However, many do not. Instead, many would prove fatal for all possible life if they were not fine-tuned.
Finally, life is demonstrably here. And the point is that no life could be here unless all 200 were simultaneously fine-tuned. Such overwhelming fine-tuning cannot rationally be explained, even in a universe as large as ours, without granting divine design. That's why doubting scientists have had to resort to alternate universe theories--which by definition can never be detected.
Positing highly implausible life-forms is much the same kind of dodge.
Some other brief points, the Milky Way is an uncommonly large galaxy - amongst the largest - so it is nonsense to suggest a "too large" galaxy would "disturb the sun's orbit" (whatever that bit of nonsense means) and "ignite too many galactic eruptions" (for whatever undisclosed reason). There are no galaxies sufficiently larger than the Milky Way as to follow a meaningfully different dynamic; we are already an unusually large galaxy.
What the heck is a "too elliptical" galaxy? Whatever it is, we already know that elliptical galaxies have way more than enough heavy metals for life. Furthermore, heavy elements derive from the continuous manufacture and expulsion of these elements by the resident stars. There is nothing practically different about this between an elliptical and a spiral galaxy once the stars are present. What does the shape have to do with it.
We are currently colliding with two galaxies and will in the future collide with the Andromeda Galaxy. The odds that this will disrupt the earth's orbit are infinitesimal. Galactic collisions primarily involve gravitational interactions on a super-macro scale. The Andromeda collision will present little threat to earth except in the most unlucky of circumstances. The current collisions obviously aren't disrupting us.
And on and on...
And, very broadly speaking, many of the features noted in the central parts of that list are those one would expect of any star of that general type. The sun is a very typical star of its type with an average size and temperature. There are many billions of similar stars in the galaxy with similar characteristics well within the range necessary for earthly life. A number of items involve the general location of the star within the galaxy. There is a considerable range within the galactic disc with comparable conditions and many, many billions of stars within that range. Other items involve the composition of our atmosphere - which has been engineered by life forms and would thereby be a consequence, not a prerequisite of life - or the composition of elements, which should be roughly typical of any rocky planet of this general type.
Many items are just inanity, with no basis that I can discern (e.g., if too much in the spiral arms: life-supportable planet will be destabliized by the gravity and radiation from adjacent spiral arms). That's simply stupid and wrong; what more is there to say about it? So much of this reveals such a comprehensive ignorance about astronomy, physics, and biology that it's just not worth bothering with.
So far as we can tell, the Milky Way is a fairly typical spiral galaxy except for being on the large side and somewhat barred. I have no clue how a spiral galaxy would have a 'too large' or 'not large enough' nuclear bulge. In other words, to the best of my knowledge, all spiral galaxies have a sufficiently large but not overly large nuclear bulge. So, for ours to have an adequate but not excessive bulge doesn't strike me as extraordinary..
Similarly, what an "inadequate flow of heavy elements" or an "inadequate outward drift of stars" could be is lost on me. A spiral galaxy is a spiral galaxy and I can't think of what within the parameters of a spiral galaxy would qualify as "inadequate" for either factor.
The authors are PhDs in Astronomy (Ross) and Biology (Razale). If you scroll down below the list, you'll find 226 reputable references.
You're steadfastly opposed to my post, but I still maintain you're still just scratching the surface. Let me recommend Dr. Ross' and Dr. Razale's books. If you read them and still object, then you can take it up with them.
Best wishes.
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Of course it's special. When I started it, I turned off 'Dinosaurs' and 'Planet-Eating Koomaron' and traded 'Binary Star System' for extra 'Hydrocarbon-laced comets.'