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.
BTW. That's not a cheap shot. It illustrates a point.
Isn't that the distance in Star Trek to that resort planet, Risa or whatever?
The range is from 0.0 to 0.92 or so, but there seem to be a number around 0.3. Somebody could chart the data if they are interested. Systematic effects was my first thought. There are a variety of methods for detection, perhaps some favor particular results. It's a valid question.
It's a level of complexity. There is lower complexity--chemicals and rock, and there is higher complexity--behavior and society. The laws of physics operate on the very lowest levels and on every level all the way up in some manner. It's not going to
With current technology -- warp drives need not apply -- we could build a giant rocket that is propelled by hydrogen bomb detonations behind a pusher plate. This concept was actually researched by the government in the 1950s and 60s and showed promised for interstellar flight (though it couldn't be operated within a million miles of Earth, and we've yet to travel a million miles from Earth, so it still isn't practical . . . but it is possible).
Anyhow, maximum speed for nuclear pulse was three percent light speed. Thus it would take three thousand years to travel ninety light years.
A multi-generational city-sized space ark would be appropriate.
That's going to take significant time to build even before the expedition sets out. We better start today.
That would sure louse up Einstein's equation E=mc2 showing energy corresponding to a mass "m" at rest. "c" is the speed of light. "E" is the total energy of a freely moving particle. If mass disappears (like in a nuclear reaction) the equivalent energy must appear. If light speed changes, so do nuclear reactions. Stars run on nuclear fusion. This presents a problem...if the speed of light were slower in the past, fusion would have been less energetic. Stars might not have even gotten "started".
All this presents a conundrum, unless Einstein's theory is seriously flawed. It has held up so far under many years of rigorous high-energy physics tests.
What part of intelligent life did you not get? That was my definition.
The point is, we are here. We are in the universe. We are definitely not confined to this little orb on which we find ourselves. Given enough time, life will be spread all throughout the galaxy (if not the universe) simply because that's the way we are. So while your position might be true in the here and now- it is demonstrably not going to be true forever. So it isn't a reliable position around which to build a belief system.
Second. Regardless of whether you believe in creation or evolution, it is a perfectly rational conclusion at which to arrive to assume that there is more life out there somewhere. If evolution is a natural occurance, it would be more surprising that it didn't happen in other places (given the unfathomable size of the universe) than to learn that it did. Likewise, if we were created by a higher intelligence (aside from the fact that its existence would constitute life outside the confines of Earth) it would be totally natural to assume this creator fostered life elsewhere. It's not to say that assumption would be correct- but it would be totally rational to assume he/she/it did.
Given the vast scope of the universe, life elsewhere in it is a sure bet. If you're playing the odds, life is where you put your money.
Yes; Jupiter-like planets in a Jupiter-like orbits are like "Hoover's" of the solar system, vacuuming up all the detritus that could end life as we know it on Earth.
So essentially, they are thought of as being a necessary condition for life to form and flourish on an Earth-like planet.
You left something off there?
At any rate:
The laws of physics operate on the very lowest levels and on every level all the way up in some manner.
With you totally there.
Hypothesis, assumption, speculation, maybe.
Conclusion? Hardly.
Oh yeah. It is my conclusion that there is life out there. Like it or not.
Apparently. Was interrupted by the real world and simply sent without editing.
When you accelerate a body to relativistic speeds, you come upon some real problems. First, you are blue-shifting all background and stellar radiation into the high-energy realm. Somehow one must shield the delicate life-forms aboard from this constant blizzard of gamma and x-rays.
Second, if any matter is in the path of the craft, how will the craft avoid it? Almost as soon as its photons arrive to announce its presence the object itself will be hot on the heels of the "message".
Third, time will shorten considerably (depending on how close to c the craft accelerates). 6 months' ship travel time to HD70642 at 99.9% c still will be 90+ years here on Earth. Friends and relatives of the astronauts will be long gone when they return.
Sure, I prefer the physics of Star Trek, but I don't think it's practical; it may not even be possible.
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