Posted on 07/03/2003 10:22:13 AM PDT by RightWhale
Astronomers find 'home from home' - 90 light years away!
Astronomers looking for planetary systems that resemble our own solar system have found the most similar formation so far. British astronomers, working with Australian and American colleagues, have discovered a planet like Jupiter in orbit round a nearby star that is very like our own Sun. Among the hundred found so far, this system is the one most similar to our Solar System. The planet's orbit is like that of Jupiter in our own Solar System, especially as it is nearly circular and there are no bigger planets closer in to its star.
"This planet is going round in a nearly circular orbit three-fifths the size of our own Jupiter. This is the closest we have yet got to a real Solar System-like planet, and advances our search for systems that are even more like our own," said UK team leader Hugh Jones of Liverpool John Moores University.
The planet was discovered using the 3.9-metre Anglo-Australian Telescope [AAT] in New South Wales, Australia. The discovery, which is part of a large search for solar systems that resemble our own, will be announced today (Thursday, July 3rd 2003) by Hugh Jones (Liverpool John Moores University) at a conference on "Extrasolar Planets: Today and Tomorrow" in Paris, France.
"It is the exquisite precision of our measurements that lets us search for these Jupiters - they are harder to find than the more exotic planets found so far. Perhaps most stars will be shown to have planets like our own Solar System", said Dr Alan Penny, from the Rutherford Appleton Laboratory.
The new planet, which has a mass about twice that of Jupiter, circles its star (HD70642) about every six years. HD70642 can be found in the constellation Puppis and is about 90 light years away from Earth. The planet is 3.3 times further from its star as the Earth is from the Sun (about halfway between Mars and Jupiter if it were in our own system).
The long-term goal of this programme is the detection of true analogues to the Solar System: planetary systems with giant planets in long circular orbits and small rocky planets on shorter circular orbits. This discovery of a -Jupiter- like gas giant planet around a nearby star is a step toward this goal. The discovery of other such planets and planetary satellites within the next decade will help astronomers assess the Solar System's place in the galaxy and whether planetary systems like our own are common or rare.
Prior to the discovery of extrasolar planets, planetary systems were generally predicted to be similar to the Solar System - giant planets orbiting beyond 4 Earth-Sun distances in circular orbits, and terrestrial mass planets in inner orbits. The danger of using theoretical ideas to extrapolate from just one example - our own Solar System - has been shown by the extrasolar planetary systems now known to exist which have very different properties. Planetary systems are much more diverse than ever imagined.
However these new planets have only been found around one-tenth of stars where they were looked for. It is possible that the harder-to-find very Solar System-like planets do exist around most stars.
The vast majority of the presently known extrasolar planets lie in elliptical orbits, which would preclude the existence of habitable terrestrial planets. Previously, the only gas giant found to orbit beyond 3 Earth-Sun distances in a near circular orbit was the outer planet of the 47 Ursa Majoris system - a system which also includes an inner gas giant at 2 Earth-Sun distances (unlike the Solar System). This discovery of a 3.3 Earth-Sun distance planet in a near circular orbit around a Sun-like star bears the closest likeness to our Solar System found to date and demonstrates our searches are precise enough to find Jupiter- like planets in Jupiter-like orbit.
To find evidence of planets, the astronomers use a high- precision technique developed by Paul Butler of the Carnegie Institute of Washington and Geoff Marcy of the University of California at Berkeley to measure how much a star "wobbles" in space as it is affected by a planet's gravity. As an unseen planet orbits a distant star, the gravitational pull causes the star to move back and forth in space. That wobble can be detected by the 'Doppler shifting' it causes in the star's light. This discovery demonstrates that the long term precision of the team's technique is 3 metres per second (7mph) making the Anglo-Australian Planet Search at least as precise as any of the many planet search projects underway.
nothing more
(see tag)
What tag? Is this is a new tact: refer to a cite that does not exist, rather than allow me to examine and existing, but bogus cite and it's irrelevant contents?
How clever. Since you are back, and since you apparently don't want to discuss anything relevant to this thread, let's just continue where we left off:
Could you supply us with a cite, or part of cite, not written by you, that backs up your contention that Darwin committed plagarism? It would seem to me to be an event of historical note, yet I don't find it in my regular history books.
I'm not sure I follow. Did Darwin make mention of earthlike planets? It would seem to me, if anything, evolution might predict whether life would arise on these other planets- not predict the existence of the planets themselves.
What are you talking about? I have not a clue.
I was responding to one of your posts:
btw - does evolution further or support conservatism?
I don't have a clue what other thread you're referencing. I simply wanted to know why you asked this question. That's your post number 55.
1 year.
Those would be the folks on the "B" ark. Along with all the Telephone Sanitizers and Advertising Executives and Management Consultants.
The idea that matter rearranges itself and produces new things, perhaps of greater organization is evolution, a concept, a set of procedures. It might be applied to try to organize knowledge of how life arose and how the unnumbered varieties of life came to be. It can also be applied to how the very same protons and quarks that were once just gas became parts of stars and parts of planets and parts of simple chemicals and parts of extremely large molecules and parts of microbial cells and parts of our own bodies and parts of things we make to support our culture and society. In order of complexity.
This is not how I learned evolution in school. What I learned in school never talked about the creation of the universe or galaxies or planetary systems. It confined itself to dealing with how life- as we experience it here on Earth- arose on this particular planet. I never recall Darwin making mention of how it all inevitably started. Maybe I was asleep in class that day?
Fascinating, however, I do not detect in this cite any point relevant to either question on the table. Where, in this cite, is it demonstrated that, because some marxists and fascists believe in darwinian theory, or find darwinian theory "handy". That that somehow therefore scientifically invalidates Darwinism? It plainly does not. The social consequences of adopting a theory are not a logically relevant measure of it's truth or falsehood.
Assuming you were addressing the other conversation: where, in this cite, is it demonstrated that Darwin was a plagarist? Again, I see no nothing remotely relevant to the point in at hand.
Oh, and just to keep the table up to date--what was the (tag) to which you previously referred. Is this it? If so, how is this cite relevant to your suggestion that I am lying (which I am not, merely speculating) as to why you provoke some threads out of existence and leave others stand?
Oh, and while you are at it--could you supply that cite you accidently overlooked supplying in the previous discussion as to where I offered some sort of rude epithet toward the bible? I take that one sort of personally, and would very much like you to cite a demonstration that you are not simply making it up.
I was looking for the StarTrek Warp speed calulator... :)
I think I heard somewhere that the total mass of the asteroid belt is only about 1/4th of a planet, debunking the "exploded planet" theory.
Another interesting theory is Bode's Law, that the orbital distances of the planets are roughly 4+3x2^n where n is the position in the sequence (divide by 10 to get Astronomical Units). Mercury (4)/10 = .4AU (36MM miles), Venus (4+3x2^0)/10 = .7AU (67MM), Earth (4+3x2^1)/10 = 1AU (93MM), Mars (4+3x2^2)/10 = 1.6AU (141MM), Ceres (4+3x2^3)/10 = 2.8AU, Jupiter (4+3x2^4)/10 = 5.2AU (483MM), Saturn (4+3x2^5)/10 = 10AU(886MM), Uranus (4+3x2^6)/10 = 19.6AU(1,783MM). The "law" breaks down after Uranus. The intersting thing is that the asteroid belt fits right where the next planet ought to be.
-PJ
Since there's not much of a way to guess what size the planet in question originally was, or how it exploded, and therefore, how much of its mass would rightfully be expected to remain in a matching orbit, that seems like a rather doubtful datapoint to me.
You have to fudge a little to make Bode's law fit our solar system. Not much, but enough to leave room for doubt. Their are other possible explanations that haven't been exhausted yet.
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