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Potential 'Avatar' Gas Giant Exoplanet Discovered
Luminary Crush writes "A gas giant of approximately 1.5 Mj (Jupiter Mass) was discovered on October 22nd around the binary star system HD 176051B. It's not known with certainty which component of the binary system the planet is in orbit around at this point as both stars in HD 176051B are relatively Sol-sized (1.07 and .71 solar masses). Named 176051B b, this new exoplanet orbits within the star system's habitable zone, and if mapped onto our solar system with relative distance from our Sun it would place the large planet between Earth and Mars. While it's unlikely that such a gas giant could host life as we know it (though it's hypothesized), the location of the big planet opens up the intriguing idea of the realization of some of science fiction's famously habitable moons, Pandora and Endor. Look no further than our own solar system to see moons with the potential ingredients for life — just add heat."
So, it's a much farther distance (50 ly), has a binary system (instead of a triple system), and the planet is bigger than Jupiter (instead of smaller).
How is this related to Polyphemus from Avatar more, than, say, Bespin? ... come to think of it, both Avatar and this discovery are both overhyped. Objection withdrawn.
short answer: If [Jupiter] were about sixty times more massive than it is, it would indeed be a star!
The minimum size of a star is thought to be about 83 times the mass of jupiter.
1.5 Jupiter Masses = 2.8479 * 10^27 kg, in case anyone was wondering.
If intelligent life evolved out of a moon ecosystem where the main source of heat was tectonic stress, and the main liquid was methane or ammonia, you can bet they'd kick our ass.
-- thinkyhead software and media
in a fusion powered orion, it falls far short of the 50 year rule; 500 years with current technology. If we found a plentiful antimatter source, we could cut this to about 60 years.
"People don't want to learn linux" hasn't been a valid excuse since '03.
Note, if we get an efficient engine that can keep accelerating (no "idle flight" period), it would be 60-70 years for earth-based observers, but much shorter for the crew. The speed limit of 1c is relevant to surrounding universe, but from the spaceship crew standpoints, the engine power - acceleration - speed - distance - travel time relation behaves in mostly newtonian way. If they expend power needed to travel at 10c according to newtonian mechanics, it will take (in their perception) 1/10 the time of travel at 1c to get there.
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The Cosmos Series had a very good explanation of floaters and sinkers and some predators etc... /huh huh huh floaters.
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I didn't know mass was a unit at all ;)
When talking about how big something needs to be to become a star though, mass is pretty much your only useful measure.
...and yet we sort of have just such a thing in our system - a moon hot to the point of being, by far, the most volcanically active body in the system.
All this ignoring how many extrasolar hot Jupiters and hot Neptunes we're discovering - you people really never heard about them, about planetary migration in general?
One that hath name thou can not otter
Of course, you could heat the environment of an already-existing gas giant, but how would that happen?
Yeah, how in the universe this could ever be possible?
One that hath name thou can not otter
If we found a plentiful antimatter source, and built something never yet produced but only really theorised (i.e. an antimatter-based propulsion of any kind), and make it into a fairly compact but reliable propulsion system, of which one example is bought and attached to a particular extra-solar-capable chassis (of which the only two ever produced were made in the 70's and are currently used to transport a couple of LP's in a random direction that we have no control over any longer), etc. etc. etc.
As with anything to do with extra-solar propulsion, we won't see it for many, many decades and when we do, almost all our extra-solar attempts will be embarrassingly overtaken by the next-decade's attempt that will go faster (and the original mission will either have to keep going to somewhere that will be already colonised / studied even if it takes several generations, or turn back and spend their entire lives and those of their grandchildren trying to get back to Earth, or have to "merge" with the new attempt and thus have spent all their lives in a tin can when they could have just sat on Earth).
The best solution, if we were to put all our efforts to getting to any such system (which seems unlikely and extraordinarily risky), would be something based on the "water-in-the-desert" method. Go a bit of the way. Leave a small cache of supplies / fuel / resources. Return. Go again, but a tiny bit further, and leave more stuff. Go again and leave more stuff. When we have sufficient stuff cached, make a SECOND cache and so on.
In spacecraft terms, that means making something that can get to the moon easily. When we have that as an ordinary operational service, we can make trips to the next planet ready. When we have regular trips to all the planets, we can start veering slightly out of the solar system. When we have that ready, we can actually aim for the next best system by firing our best ships at it. They *will* get overtaken, but we can overtake them with an almost-empty ship with better technology, absorb their knowledge/resources and continue on the journey. Then the next ship will overtake that, pick them all up, melt down the old ship for repair-metal and continue. Eventually the people would get to some other system but we can't *ever* expect to just shoot something at the stars and expect it to work.
This isn't the Moon (a mere ten-times the Equator's distance, and your average reindeer can travel the distance of the equator about 2-3 times during his life, your car should be able to do about four-equators-worth of travel easily before it finally dies (all of mine have), etc.). This is another solar system (the NEAREST of which is 4.37 light years, which is 1,033,339,810 (and a bit) equators. A BILLION equators. And that's the NEAREST damn thing, and quite boring really.
50 years is way, way, way, optimistic for even a probe to another systems (hell, we've only "recently" done it with a probe out of the solar system at all, or a probe on another planet) - such a propulsion system would basically solve every energy need on Earth, so it's not a "small" development. To be honest, even 100, or 150, or 200 years, is being optimistic. Sometimes optimism pays off but we're not even just talking about doing something which we haven't done, at all, anywhere, in over 40 years - set foot on something that you could, theoretically, drive to within a few years in an ordinary car if you could pave a road there. We're talking about improving the entire accomplishments of all space travel by several (possibly dozen) orders of magnitude in only 2, 3 or 4 times the entire history of space travel itself (i.e. somewhere so far away that parts of a car would probably have destroyed themselves through their own radioactive half-life before it got even close).
If we could do that with cars, extrapolating from the 60's, then we'd all be driving 1000mph cars that get 500mpg (actually, probably a LOT more than that).
It's not *impossible*, it's just silver-suits and three-course-meal
Note, if we get an efficient engine that can keep accelerating (no "idle flight" period), it would be 60-70 years for earth-based observers, but much shorter for the crew. The speed limit of 1c is relevant to surrounding universe, but from the spaceship crew standpoints, the engine power - acceleration - speed - distance - travel time relation behaves in mostly newtonian way. If they expend power needed to travel at 10c according to newtonian mechanics, it will take (in their perception) 1/10 the time of travel at 1c to get there.
Ok... Now I understand why we haven't traveled to the stars yet.
We must overestimate the power needed, so that we can underestimate the time required.
This is opposite from all engineering projects on earth, where the final design is underpowered and delayed.
I am an author of the paper in which this discovery was reported. You can find a copy of the paper here.
While the planet probably is near the habitable zone, this isn't the first time a giant planet has been found in the habitable zone of a star, and while it could have moons, there isn't any reason to speculate more about this planet than any of the others.
However, this planet is important for two other reasons:
1. It was the first planet discovered using a technique called "astrometry", which is measuring the positions of stars in the sky, as the move up/down and left/right in reaction to a planet orbiting it. This technique has the potential to find earthlike planets in the habitable zones of nearby stars.
2. It is found in a binary system and the second star is close enough that its gravity would have impacted planet formation. The leading theory of planet formation, called "core accretion", requires millions of year for planets to form, as dust in a disk around the star collides together and clings electrostatically (similar to the way dustballs collect on a hardwood floor). Eventually the dustballs grow large enough to be considered rocks, those collide and grow bigger, etc. But the second star's gravity would cause the dust to be swept out of the system in just thousands of years, far too little time for core accretion to occur. Thus, we need a different mechanism to explain planet formation in this system. This isn't the only such binary, but it this study does offer more controlled statistics of how frequently such binaries host planets, and these facts combined show that some had to form in the binary itself---the chances of a binary interacting with another star (that originally hosted the planet), leading to an exchange where the binary picks up the star, are much too small to explain the high rate observed.
Also, here is another press story covering the discovery (by the way, stars have multiple names---don't be confused that this article calls it "HR 7162" and the other one refers to "HD 176051"---they really are the same system). The third figure on the right hand panel is particularly useful.
Any questions? I'll try to answer responses to this post.
1 x the mass of Jupiter... you just need to add enough monoliths.
Yes, but the "nice 1g" (wow, artificial gravity problem solved!) gives us about 1 light year/year^2 acceleration. That is, gain/loss of 1c per year.
About 4 years to Proxima Centauri. 50 light years in mere 7 "subjective" years. 40 years of crew life would give 800 light years of travel distance. About 1000 parsecs in a lifetime.
Sure, we would still need engines that can provide sustained 1g. We're nowhere near that. We have rocket monstrosities that are barely survivable at 8g and more for minutes a time, and tiny farts of ~1N that can work for many years a time. Nothing in between. I believe a pure sustained fusion rocket might be capable of reaching Centauri stars, but that's still a long way away.
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It's not known with certainty which component of the binary system the planet is in orbit around at this point as both stars in HD 176051B are relatively Sol-sized (1.07 and .71 solar masses).
Orbits do not work that way. The planet is orbiting around the center of gravity of the binary star/planet system. Since this is a binary star, this very well might be a point in empty space.
Give me Classic Slashdot or give me death!
The galaxy is really, really, really big. There are lot's and lot's of stars. Really. There are a whole slew of them.
Finding as much interesting stuff as we possibly can now, will help tremendously when we finally have the technology to send probes in a reasonable time.
And developing new techniques for searching for interesting stuff is important as well.
If we listened to you, in 100 years or so when we can send something somewhere, we would just have to cross out fingers, close our eyes, and point somewhere in the sky when picking where to go.
What good does it do to know that habitable exoplanets are out there? Can we send people there? And even if we did ... (rest of depressing post)
Tiger got to hunt
Bird got to fly
Man got to sit and wonder - why, why, why?
Tiger got to sleep
Bird got to land
Man got to tell himself - he understand.
(Kurt Vonnegut, Jr.)
Faster! Faster! Faster would be better!
Looking back at historical examples of human migration on vast scales, the typical amount of time that somebody relocated from say one continent to another was usually on the scale of months, to perhaps a year or two. A trip from Germany or Poland to California in the 1850's took approximately about a year, including travel by ship to one of the eastern US ports, and then overland on foot or wagon.
I note this because that is about the current level of technology in terms of travel to various destinations around the Solar System at the moment, and one of the reasons why I think it is going to be comparatively trivial to make the trip to locations of that nature. Interstellar distances are going to take a leap of logic to move out that far and even with "exotic" but physically possible (Relativity equations don't keep you from making the trip as you suggest) modes of travel. At least right now, if you make a trip to Mars you can cut your losses and return to the Earth even using a Hohmann transfer orbit doing a minimal delta-v flight in a lifetime.... you can do several trips of that nature, much less something with more exotic propulsion like a nuclear rocket engine or something else similar.
Somebody making a trip to Alpha Centauri might be able to make a return trip... if they really care to. But by the time they return home nearly everybody that they cared for would be dead from old age including newborn infants they might have known before they left.
As you have suggested here, it is something possible and within 800 lightyears I'm fairly certain that we might be able to find a place at least as habitable as Mars that would be worth the trip out there to build homes and make a life. My question is.... why would we?
Life would have to be getting pretty ugly here in the Solar System for somebody to be that motivated to travel those kinds of distances.
Yes, these calculations include that.
4 light years to Proxima, top speed of 2c at halfway point, averaged speed 1c, 4 years to get there. It would be much shorter for a speedy fly-by, accelerating all the time.
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There are 6 billion people. Do you really believe none could be found desperate/crazy/naive enough to want to go there?
btw, Centauri at 1g roundtrip would take 8 traveler's years and only ~12 earth years. Not quite as bad.
Still, with E=mc^2, to get 1kg to 2c equivalent you need to burn 2kg of matter in a nuclear fusion entirely. Plus whatever is needed to bring last of that fuel near the 2c... rocket fuel equations apply. That's why Proxima may be still within reach, further places - not quite.
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I'm having a dilemma on whether this should get modded 'Informative'.
Divide a cake by zero. Is it still a cake?