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.”
If it wasn't for me, the universe wouldn't exist.
This would be like calling up one random person in Peru to get the average political opinion here on the entire world.
Ahh yes, the Kerry/Edwards campaign poll.
I only read over material from Hugh Ross, the astrophysicist. Based on his bio, Dr. Ross thinks he sees the imprints of God, and is a Christian first and foremost. Gazing at the universe through that prism is fine with me if it makes him happy, but it does rather little to commend his scientific reason and objective judgment so far as I'm concerned. His "unshakable confidence that God's revelation of Himself in Scripture and nature do not, will not, and cannot contradict" obviously drives his mental exercise to reconcile the two. He may be better off for that, but the scientific merit of his hypotheses are clearly not as a result.
PS. There is no reason for me to bother reading their books because there is nothing down this line of reasoning that would induce me to change my view in this regard. At most, they would reinforce a view that I already tend toward: that civilizations are rare. I have no problem with even the notion that we are one of a handful of sentient beings in the universe, although I would guess there are tens of billions (just one on average per spiral galaxy very similar to ours would give that result).
Suit yourself. But I warn you, now you've got me praying for you! Your screen-name implies rejection of authority, and God is the ultimate authority, so I think I'll start there.
Al Gore thought the sun was a General Electric space heater. Who would have thunk?
Here's some stuff on planetary orbits (Java)
http://burtleburtle.net/bob/physics/orbit101.html
Here's the site's main page.. Lotsa science stuff..
http://burtleburtle.net/bob/index.html
Well, rest assured I can use all the prayer I can get! ;^)
That's the right attitude--we all can. Best wishes.
Actually the opposite is more logical...
The more the count, the more probably their are "usual charactistics".. and less options..
Bon voyage. Don't forget to take alot of food.
How is that statement true? If Earth were 1% farther from the sun-we'd be colder, but not as cold as we already have been in ice ages. The ice age didn't break down our water cycle, so why would a slight difference in orbit do it?
The 1% is a quote from a previous post. Beats me if it's true or not.
My point was that we know, to an extent, how things work here on Earth. We may know that we need evaporation and rain to live and that a different climate would disrupt this.
I don't see how we can prove that there are no other ways for life to exist. We are only recently finding life in some very hot and some very cold places, for example.
Please see Dr. Hugh Ross' website, reasons.org.
Any "simple life" found on Mars (eventually, it is inevitable) will be earth-life blown into outer space by meteoritic collisions with earth and then blown to Mars by solar wind.
Life is fragile, and Ross' limited parameters are sensible. Bear in mind that it is not the tightness of those limitations, but rather the great number of limiting parameters, which squeezes the odds so unbearably tightly.
The fact that the scientific consensus is that this universe cannot support more than the single life-development planet we live on, and that therefore the only hope is in other universes, is fatal to your speculation.
As to that list of parameters: over the past twenty years I've watched it grow from less than forty to over two hundred. Each is independent and based on solid research, as indicated by the references below the list. Naturally, I'm not going to argue thjem individually with you, although I honor your willingness to grapple with them. Instead, I'll point out that Dr. Ross has covered them in depth in his books; moreover, Reasons to Believe has a daily hotline, so you can pose these challenges to his volunteer staff--see the reasons.org website for the phone number and times.
Best wishes.
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