08 Aug 08
Originally posted by sonhouseInteresting but is seems that there's a lot of assumptions made to get the simulation to run fast enough. Furthermore, our ability to detect other planets is a bit on the limited side at the moment. We have found a few hundred and none at all directly. I'd suggest the amount of data we have on exo-planets is too limited to be drawing much in the way of conclusions and therefore it is better to take most data from the ones we can see close up.
http://www.physorg.com/news137337086.html
This study shows how different our solar system is compared to the 300 planets around a lot of stars nearby, they are nothing like the jewel that is our solar system and the absolute jewel that is the Earth.
On another completely subjective point. All through history, we have considered our position special and each time, with new discoveries, we have found we're not.
08 Aug 08
Originally posted by WheelyBased on the evidence we do have, its the size and position of the planets we found, like super Jupiters whose year is a few days, it's so close to the sun. When you start seeing this time after time, it doesn't really matter whether there are earth sized planets around, they have probably been flung out to the edge of the solar system and out of any potential for liquid water. That is the gist of that study. 300 planets is a big enough sample to satisfy the laws of statistics.
Interesting but is seems that there's a lot of assumptions made to get the simulation to run fast enough. Furthermore, our ability to detect other planets is a bit on the limited side at the moment. We have found a few hundred and none at all directly. I'd suggest the amount of data we have on exo-planets is too limited to be drawing much in the way of con ...[text shortened]... considered our position special and each time, with new discoveries, we have found we're not.
08 Aug 08
We've found some stars with planets. We've never found stars with small planets, especially with wide orbits around the motherstar. So we don't really much about planetary systems, yet.
The most special with our own planetary system, and espacially with our own planet, is that we live there. Nothing more.
We just don't have statistics enough to make any conclusions.
08 Aug 08
Originally posted by sonhouseLooking at the article, they admit to having made choices based on pretty much gut feeling (they don't use that phrase) in order to speed up the simulation. It looks kind of suspect to me.
Based on the evidence we do have, its the size and position of the planets we found, like super Jupiters whose year is a few days, it's so close to the sun. When you start seeing this time after time, it doesn't really matter whether there are earth sized planets around, they have probably been flung out to the edge of the solar system and out of any potent ...[text shortened]... the gist of that study. 300 planets is a big enough sample to satisfy the laws of statistics.
With regard to the actual discovery of these planets. None of them have been directly observed and we are pretty much solely relying on wobbling stars and unexpected occultations. The article discusses hot jupiters and yet we don't have to be too much larger than Jupiter to get a possible brown dwarf and therefore a binary system. How we deduce, using current methods, the difference between a planet and a large belt of asteroids or a large planet moon system is beyond me (though possibly not beyond lots of other people). To me it seems we have too little information to start adding it to our understanding of how solar systems form.
We do think we have found a near earth size planet. We have found 2.5 times earth size at the right kind of distance from a red dwarf so we are not that special given the small sample we have been looking at. Ok a red dwarf isn't probably where you want to be living but hey, most stars are red dwarfs.
08 Aug 08
Originally posted by WheelyOne problem with red dwarf's is they are very erratic and can throw off some mean plasma, lots worse than our rather placid sun. So if you do have an earth like planet in a liquid water area orbit, it gets blasted with a lot of radiation from the little darlings🙂 If the planet had a nice fat magnetic field, maybe stronger than the Earth's, maybe it would deflect most of it but those red dwarfs have really violent outbursts followed by relative calm.
Looking at the article, they admit to having made choices based on pretty much gut feeling (they don't use that phrase) in order to speed up the simulation. It looks kind of suspect to me.
With regard to the actual discovery of these planets. None of them have been directly observed and we are pretty much solely relying on wobbling stars and unexpected o ...[text shortened]... Ok a red dwarf isn't probably where you want to be living but hey, most stars are red dwarfs.
The next generation of specialty spaceborn telescopes will be a lot more capable and in ten years or so we will be detecting earth mass objects so the field will be wide open then but for now we have to rely on the analysis of what we have. I wonder when they (Europe or NASA) will launch a space born interferometer, that would be able to pin down small planets. Only time will tell.
11 Aug 08
Originally posted by sonhousesince the number of observable planets is somewhat unimpressive, and since most of those planets are jupiter cousins, i will delay my "woohoo we have the most awesome solar system ever" celebration
http://www.physorg.com/news137337086.html
This study shows how different our solar system is compared to the 300 planets around a lot of stars nearby, they are nothing like the jewel that is our solar system and the absolute jewel that is the Earth.
11 Aug 08
Originally posted by ZahlanziI will forego any delay---Yaayyy Yaayyy for the Milky Way! Sol is the best! To hell with all the rest!!!
since the number of observable planets is somewhat unimpressive, and since most of those planets are jupiter cousins, i will delay my "woohoo we have the most awesome solar system ever" celebration
14 Aug 08
1 edit
Originally posted by sonhouseThere are two statistical reasons why those 300 planets would be unlikely to represent typical exoplanets:
http://www.physorg.com/news137337086.html
This study shows how different our solar system is compared to the 300 planets around a lot of stars nearby, they are nothing like the jewel that is our solar system and the absolute jewel that is the Earth.
1, the larger the exoplanet, the easier and more likely it is that we would detect it,
2, the closer the exoplanet is to the star it orbits, the easier and the more likely it is that we would detect it.
The two facts above would mean that 300 planets would be unlikely to represent typical exoplanets. Both the larger size of the exoplanets and the closer the exoplanet is to the star it orbits, the greater the wobble it would cause of the star it orbits, and, it is mainly through the wobble it would cause of the star it orbits that these exoplanet are detected. That means those 300 planets would probably consist of planets that are both much larger and have much tighter orbits of the actual average exeplanet. Both excessively large and tighter orbits of large exoplanets would make the orbits of any Earth-size planets within the “inhabitable zone” unstable because of the gravitational effects of such large planets. If Jupiter was either 100 times larger than what it is or was closer to the sun than the Earth, it would make the Earths orbit so dangerously unstable that we probably wouldn’t be here. Thus extrapolating from those 300 planets by wrongly assuming that they are representative of typical exoplanets would give the false impression that the typical solar system is much less likely to be able to support stable-orbit Earth-size planets within the “inhabitable zone” than it actually is.
14 Aug 08
Originally posted by Andrew HamiltonThat is still conjecture at this point, obviously a possiblity but we don't have enough solid data yet to support such a statement. I am guessing within 20 years we will have a much better handle on habital zones around earthlike planets.
There are two statistical reasons why those 300 planets would be unlikely to represent typical exoplanets:
1, the larger the exoplanet, the easier and more likely it is that we would detect it,
2, the closer the exoplanet is to the star it orbits, the easier and the more likely it is that we would detect it.
The two facts above would mean t ...[text shortened]... le to support stable-orbit Earth-size planets within the “inhabitable zone” than it actually is.