Slashdot Mirror
Five Possible Life-Bearing Planets Found
devphil writes "Reuters reports that six new planets have been discovered using the gravity-wobble method. Five of them are in the "habitable zone." More details are online.
" Well, they all appear to be Jupiter size class, so are most likely composed of the same elements. The primary elements of Jupiter are hydrogen and helium gas, which combined with an enormous gravity well don't make it very friendly to carbon based life. But five of the six are in the zone that would support liquid water, deemed a life-necessary element.
Aliens were also discovered today on these planets. The extraterrestrial life forms speak with very high-pitched voices and prohibit any sort of smoking.
Overheard from Bill Gates:
..."
"Damn, another one
I am SOOOOO not a scientist, so I may be completely wrong. But, even with the existance of water on any of these planets, wouldn't the extreme gravity hinder the development of advanced eukaryotes? What kind of complex structures could evolve in an environment with a gravity far greater than that of earth?
Charlie
I will be following this thread closely, this is so completely interesting to me I can't even put it into words
-- .sig files go when they die?
Child: Mommy, where do
Mother: HELL! Straight to hell!
I've never been the same since.
Just like driving a car:
(D) to go forward
(R) to go backward
The planets themselves might have to be ruled out as possible candidates for Earth-style life, but what about any moons? The moons would have to be pretty large to be able to hang on to half-decent atmospheres, and tidal effects from the giant planet would be somewhat on the large side...
Of course, it would be immensely difficult to detect such objects, but the possibility is still there...
Tedious Bloggy Stuff - hooray?
Of course wouldn't Non Carboned Based Life be much more interesting to see. Just imagine a super slimy goo that responded to our radio signals with video streams of what Goo life was like. Goo Sports, Goo Politics, Goo Art, the possibilities are endless.
Life doesn't have to be carbon-based, nor needing water in order to survive. How about a polysilicate kind of life, probably much simpler and primitive than "life" as we know it, but maybe a lot more interesting... (stands more heat, more cold, more pressure, maybe can move by "slithering" around... who knows?) Or how about some gaseous kind of life? We sure as heck don't know anything like that right now, but nobody says gases can't evolve to something interesting, just as carbon does...
When someone says life, everyone inmediately thinks it should be humanoids... it isn't necesarily that way...
I think the concentration ought to be on looking for life elsewhere in our solar system, be it past or present. If we do find life on, say, Europa, it'd be a pretty good indication that the Universe belongs to life. Then we could say that these new planets are likely habitation zones. If all our system's candidates turn out as dead as Salt Lake City on a Friday night, then we shrug and keep looking.
I find it ironic that we live in a "modern" age, complete with space flight, and we can't even work up the energy to send serious missions to the most likely close-by homes of extraterrestrial life. I mean, imagine people looking back at the 20th century and snickering over our "life vs. empty universe" debate when the proof lay so close at hand...
----
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
I'm a student at the Uni of Sussex, one of the co-discovering institutions. Maybe I'll get to help vote on a name. That'd be wild.
Shut up me.
--Remove SPAM from my address to mail me
This discovery does have significance, not for the possibility of life on those gas giants, but because it proves that planets outside of our solar system do form in the "life zone".
As some of the news stories stated, only a tiny fraction of the stars have been identified as having a planet. Ten or twenty years will probably be required to detect some of the planets out there, based on the length of their orbital periods.
As for these gas giants... well, it is still possible that one or more of them have a moon large enough to old a decent atmosphere. That would provide a possible abode for life.
Mike Eckardt meckardt@yahoo.spam.com
If we disregard any potential life forms not based on carbon and water -- a reasonable thing to do, scientifically, since we have no data points with regards to them -- life on these planets, like life on Jupiter or in Jupiter's atmosphere -- is quite unlikely.
But if these planets are in their stars' habitable zones, then so are the moons of these planets. And one of these moons might, perhaps, be a world with plentiful water that supports macroscopic life.
(Europa, a moon of Jupiter, is widely regarded as the best candidate for extraterrestrial life in our solar system. Although it is outside the traditional 'habitable zone' of the sun, it does have an immense ice covering. Its ocean of ice is believe to extend to around 50km in depth. Beneath this ice, there may be liquid water -- and perhaps organisms living off the geothermal energy generated by Europa's gravitational interaction with Jupiter.)
Bob Kopp
"No Earth-like planets are likely to be contained in these new planetary systems, Vogt said. Jupiter-sized planets in oval-shaped or
eccentric orbits -- instead of the neatly stacked, circular orbits of our solar system -- would have such gravitational force as to
quickly eject any Earth-type planet, he said."
The planets in our solar system are not perfectly circular; they move in a slightly elliptical fashion (as shown by Johannes Kepler 400 years ago.) Also, conventional wisdom about inhabitable planets states that any such planet would have to be about earth-sized: any smaller, and the gravitational force would not be strong enough to retain an atmosphere. Much larger, and the gravitational field would be so strong as to attract large quantities of passing gas, and end up as a giant gas ball (a la Jupiter.) However, there is some postulation that Jupiter actually might be a brown dwarf (in other words, a stillborn K or M-class star), so conventional wisdom could be wrong in this regard.
I think that the odds of these new planets having moons that harbor life is low, (still non-zero however!) We will probably have to discover a far larger number of these before we come across one that contains life.
:(
:)
Still, this is not the real crux of the problem, these moons could have life on them and we will probably not be able to detect it for THOUSANDS of years. Why? The odds of the lifeforms on those moons being sufficently advanced to have developed radio or space travel or ANY form of technology is about the same of their being life there in the first place.
Why? (The astronomers and biologists amongst us probably already know this) Life on our planet took billions of years to evolve to the point where a civilization capable of technology appeared. The amount of time that we have possesed technology compared to the amount of time that life on our planet existed as nothing but simple prokyarotes is insignifigant. So, if there is life around these stars it is most likely in a very simple form (or so far advanced as to make our current technology equal to the discovery of fire.)
I only wish there was some way that we could go to these stars and check. Alas this will not happen in my lifetime, or even the lifetime of many of my ancestors.
Just thought I would add all that because I can forsee some of the quesions in advance.
Try to hack my 31337 firewall!
They recently managed to collect some of the light reflected off another large planet in orbit around another star. This planet was very close, but very large, and was composed of, IIRC, magnesium, silicon, and potassium (oxygen was also found in trace amounts, which was the big story with this report), which are all very heavy elements. The fact is, we're not quite sure what makes planets have the makeup they do, but the theory that I'm most familiar with says that the solar wind blows most of the lighter elements (helium and hydrogen, for example) out past a certain region, which is why the inner planets contain heavier elements. These planets may very well be something similar to Earth, or, more likely, a planet composed of terrestrial elements compressed into a form we haven't seen before.
Keep holding out hope, Mulders.
The planets have aliens on them, and they obviously must have computer systems... And -their- systems don't run Windows! They probably don't even have a 0.2% market share in the universe!
At http://www.cnn.com/TECH/space/9911/29/space.planet s.reut/ there is a great article about this discovery. They actually discovered 6 planets, 5 of which are somewhat hospitable to life.
Rajiv Varma
Fire, Water, Earth, Wind.
And, of course, don't forget Turbonium.
The size and composition of these planets effectively rules out Life As We Know It (tm). But, they are deemed to be "possibly life-bearing" because they could contain liquid water. Why is liquid water important? Because it is essential for Life As We Know It (tm), which, as has already been admitted, could not exist there.
The question is, will we be able to recognize non-carbon-based life-forms as life-forms? I mean, it's like the old question, "Is fire alive?" It follows all the basic characteristics of life (consumption, reproduction, waste removal, death, etc.), but we know that it's a chemical reaction. I remember I asked my science teacher if we ourselves weren't simply chemical reactions and she was rather stumped. I don't remember the final answer of why fire isn't life (anyone care to refresh), but I remember it satisfied me at the time (or maybe the bell rang).
The point is, we may not recognize life as such, and if so, is it still life? I mean, the Earth operates on a very life-like series of system, so is it 'alive', and if so, does that make it a life-form? Same kind of thing with viruses.
...
SANTA CRUZ, CA--The world's most prolific team of planet hunters has found six new planets orbiting nearby stars, bringing the total number of planets astronomers have detected outside the solar system to 28. The researchers also found evidence suggesting that two previously discovered planets have additional companions, said Steven Vogt, professor of astronomy and astrophysics at the University of California, Santa Cruz.
Vogt and his colleagues, Geoffrey Marcy of UC Berkeley, Paul Butler of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington in Washington, D.C., and Kevin Apps of the University of Sussex, England, made the discoveries using the High Resolution Echelle Spectrograph (HIRES, designed and built by Vogt) on the Keck I Telescope in Hawaii. Their findings will be published in the Astrophysical Journal.
The researchers have been using the facilities at the W. M. Keck Observatory for the past three years to conduct a survey of 500 nearby sunlike stars in search of planets. The project is supported by the NASA Origins Program, which has provided both funding and telescope time, and by the National Science Foundation.
The six new planets increase by about 25 percent the number of known "extrasolar" planets, giving astronomers a substantial amount of additional information about planetary systems, Vogt said. One of the planets, HD 192263, was also recently detected by Nuno Santos and collaborators in Geneva, Switzerland, who reported it while Vogt and his colleagues were preparing their paper.
The new planets orbit stars that are similar in size, age, and brightness to the Sun and are at distances ranging from 65 to 192 light-years from Earth. The planets themselves range in mass from slightly smaller to several times larger than the planet Jupiter (0.8 to 6.5 times the mass of Jupiter). They are probably also similar to Jupiter in their compositions--basically giant balls of hydrogen and helium gas, Vogt said.
The presence of a planet around a star is indicated by a telltale wobble inthe motion of the star as a result of the gravitational force exerted by the orbiting planet. Vogt and his coworkers recently achieved independent confirmation of this method for detecting planets when they were able to predict and measure the dimming of a star as a planet passed in front of it.
The orbits of the new planets, like those of most of the extrasolar planets discovered so far, tend to be quite eccentric, tracing paths that are oval rather than circular. One of the planets, around a star called HD 222582, has the most wildly eccentric orbit yet known, carrying it from as close as 0.39 astronomical units (AU: the distance from Earth to the Sun) to as far as 2.31 AU from its parent star in the course of its 576-day orbit.
"It is beginning to look like neatly stacked, circular orbits such as we see in our own solar system are relatively rare," Vogt said.
Interestingly, five of the six planets are located within the so-called the motion of the star as a result of the gravitational force exerted by the orbiting planet. Vogt and his coworkers recently achieved independent confirmation of this method for detecting planets when they were able to predict and measure the dimming of a star as a planet passed in front of it.
The orbits of the new planets, like those of most of the extrasolar planets discovered so far, tend to be quite eccentric, tracing paths that are oval rather than circular. One of the planets, around a star called HD 222582, has the most wildly eccentric orbit yet known, carrying it from as close as 0.39 astronomical units (AU: the distance from Earth to the Sun) to as far as 2.31 AU from its parent star in the course of its 576-day orbit.
"It is beginning to look like neatly stacked, circular orbits such as we see in our own solar system are relatively rare," Vogt said.
Interestingly, five of the six planets are located within the so-called "habitable zones" of their stars. This is the region where temperatures would allow water to exist in liquid form. Most of the extrasolar planets the researchers have studied have turned out to be outside the habitable zone, either too close to their star or too far away, and therefore too hot or too cold, Vogt said.
"These planets are at just the right distance, with temperatures in one case around 108 degrees Fahrenheit--like a hot day in Sacramento," he said.
Planetary systems with Jupiter-sized planets in oval-shaped orbits are not expected to harbor Earthlike planets, Vogt added. In fact, if an Earthlike planet were put into such a system, it would be quickly ejected by the gravitational influence of the Jupiter-mass planet. Vogt noted, however, that if these Jupiter-sized planets are similar to those in our own solar system, they probably have numerous moons associated with them.
"For a planet in the habitable zone of its star, such moons offer the possibility of liquid water and the eventual emergence of life," he said.
In addition to the discovery of six new planets, the researchers gathered new data on four previously known planets. Two of them, around the stars HD 217107 and HD 187123, showed long-term trends in their orbits indicating the presence of an additional companion. These companions, which may be planets or larger objects (e.g., brown dwarfs), appear to be orbiting their host stars in a long period, taking at least two to three years to complete an orbit, Vogt said. These findings are significant because previously only one other system of multiple planets, around the star Upsilon Andromedae, had been identified.
"It will take years of additional observations to work out the masses and orbits of these companions, but the evidence suggests there are a fair number of multiple planet systems out there," Vogt said.
Specific details about the new planets and their host stars are given below: HD 10697 is a G5IV star, slightly cooler and a bit larger than the Sun. It lies 106 light-years away in the constellation Pisces. Its planet has a minimum mass of 6.35 Jupiter masses and a 1,072-day orbit. The radius of this orbit is about 2.13 AU, but the orbit is somewhat eccentric, so the planet's distance from its star ranges from 1.87 AU to 2.39 AU. At its average orbital distance, it lies just at the outside edge of the habitable zone of its star, and is expected to have an equilibrium temperature (due to energy received from its parent star) of about 15 degrees F.
HD 37124 is a G4V star, slightly cooler than the Sun. It lies 108 light-years away in the constellation Taurus. Its planet has a minimum mass of 1.04 Jupiter masses and a 155.7-day orbit. This orbit is also quite eccentric. At its average orbital distance of 0.55 AU, it sits just within the inner edge of the habitable zone of its star, and is expected to have an equilibrium temperature of about 130 degrees F. This is the lowest metallicity star known to have a planet.
HD 134987 is a G5V star, 83 light-years away in the constellation Libra.Its planet orbits in a 260-day eccentric orbit. This planet has a minimum mass of 1.58 Jupiter masses. At its average orbital distance of 0.81 AU, its expected equilibrium temperature is a balmy 108 degrees F. It lies well within the habitable zone of its star.
HD 177830 is a K2IV star, about 1,000 degrees Kelvin cooler than the Sun, lying about 192 light-years away in the constellation Vulpecula. It harbors a 1.22 Jupiter mass planet in a 392-day, highly eccentric orbit. This orbit carries the planet from as close as 0.63 AU from its star to as far as 1.57 AU. At its mean orbital distance of 1.10 AU its expected temperature is about 192 degrees F. The planet is probably within the habitable zone of its star.
HD 192263 is a K2V star lying 65 light-years away in the constellation Aquila. A planet around this star was first reported by Nuno Santos, a Portuguese graduate student at the University of Geneva. Vogt's team has obtained essentially the same results as Santos: a 0.78 Jupiter mass planet orbiting in a 24.36-day orbit. This orbit has a radius of only 0.15 AU, with little or no eccentricity. It orbits well outside the habitable zone of its star.
HD 222582, a G3V star, is a near solar twin, 137 light-years away in the constellation Aquarius. Its planet orbits in a widly eccentric 576-day orbit, which carries the planet from 0.39 AU to 2.31 AU from the parent star in the course of its oval orbit. This is the most eccentric extrasolar planet orbit yet known. The planet's expected temperature is about -38 degrees F. Its mean orbital distance places it squarely in the habitable zone of its star.
Further information about the planet search is available on the Web at http://www.physics.sfsu.edu/~gmarcy/planetsearch/p lanetsearch.html. Information about the NASA Origins Program can be found at http://origins.jpl.nasa.gov/ and about NSF's astronomy program at http://www.nsf.gov/mps/ast/start.htm.
According to the article, the habitable zone is where the temperature is right for liquid water to form. But how can they tell the temperature there? If Earth had no atmosphere, it would almost always be either too hot or too cold for liquid water. If Venus had a much thinner atmosphere, it could possibly be the right temperature to support liquid water. If they're unsure of the composition of the atmosphere, how can they know liquid water could form on these recently discovered planets?
Why? Water has *so* many advantages over any other substance know to man for the creation of life.
1) It's the nearest thing we have to a universal solvent. A lot of single celled organisms acquire the things they need to survive from what is dissolved in water (hell, even fish need the dissolved oxygen to breath).
2) Water is chemically very stable. Such stability is necessary to prevent it from interfering in the complex chemical processes that create life (like, for example, Hydrogen Cyanide)
3) Water is one of the few substances that expands as a solid; that's why ice floats. If this wasn't true, eventually, the oceans would freeze over, as more solid ice kept sinking to the ocean bottom. Of course, some water would remain as a liquid on top, and by tectonic heat, but it would be marginal.
I hope this answers your question. You have a good point (why is water important for life?), but IMO, water is a necessity for life.
"Don't mind me cutting myself on Occam's Razor"
It is more or less correct to state that such a trip is within our technological grasp, human risk factors aside -- but the reasons we haven't done such a trip are more profound than simply budgetary or nuclear weapons treaty issues.
One interesting issue is that of radiation shielding -- as most of you are probably aware, the Earth's magnetic field shields people on, say, the Shuttle from lots of nasty critters. This wasn't the case for, say, the Apollo missions, but those were relatively short -- a few days; the odds that we would get a solar flare sometime during, say, a 3-year trip to Mars and back are pretty high. Shielding from highly-massive ionized particles (stuff in that lower right-hand of the periodic table) is also tricky -- the interesting thing is that up to a fairly large amount of shielding, you end up just "slowing them down" and making them more dangerous to humans than they were before. (If you don't shield, they by and large pass through and knock apart a few things in your body on the way -- giving you, for instance, a higher chance of getting a tumor.)
There are other severe physiological effects to consider, too. Probably the most serious is a degradation of bone material that occurs in a low-G environment -- this is acceptable, sort of, for even up to a year (cf the Mir missions), but a good chunk of the life sciences community would say the risk (of increased chance of fracture, permanent degradation, etc) is unacceptable when you're talking about a several-year mission. Soooo, people have looked (seriously) at artificial gravity schemes -- spinning people around to simulate gravity. These have problems too, though -- the Coriolis force makes your intuition wrong in many cases, plus putting a rotating ring in space (for instance) requires a pretty hefty penalty in terms of the amount of mass you're propelling. (I should mention that I think these problems will eventually be worked out -- tether schemes and small-scale intermittent-use centrifuges look promising. But it'll be a while.)
All of these are surmountable, probably. (And a substantial minority of people have said that the risk factors I mention above are acceptable for a Mars trip -- astronauts are risk-takers, the thinking goes.) My point is just that it's not as simple as it might seem. I haven't even touched on more basic physical principles that make accelerating anything (much less a manned spacecraft) up to some large fraction of the speed of light a very very difficult problem. But this post is more than long enough already. :-)
On the other hand, any planet massing as much as 6 Jupiters is going to have a lot of heat left over from its formation, however many billions of years ago. It'll be warm, plenty warm. What it probably won't have is a solid surface or a liquid sea anywhere within the zone that allows for life as we know it (liquid water between freezing and maybe 250 F). Life appears to be very tenacious, but it probably has its limits nonetheless.
--
Advertisers: If you attach cookies to your banner ads,
Time is Nature's way of keeping everything from happening at once... the bitch.
Fire does react to external stimuli. It moves away from wind (normally as a physical result to the wind) and the preservation instinct of fire could well be its intention to burn. I mean, I know fire's not a life-form, but it could be if we didn't know exactly what it was an how it functioned.
Unfortunatly, it will be a while befor we find out for certain: even 1 light year is a little far to walk (~9e12km) :(
Bill - aka taniwha
--
Leave others their otherness. -- Aratak
Harry Stubbs (Hal Clement is his pseudonym) wrote a *very* entertaining story set on a very fast spinning discus-shaped planet called Meskelin, such that anyone at the equator would experience about three terrestrial gravities, while the poles
ran to several hundred gravities. A human expedition uses the locals (long wormlike creatures) to salvage a polar probe. What makes it particularly fun is the story is largely narrated from the point of view of the Yankee Trader-like Meskelinite Captain Barlennan, whose real ambition is shown at the end of the novel, "Mission of Gravity", in which he masters the hot air balloon(A sequel, "Under", is the cover story for the January 2000 70th anniversary issue of ANALOG currently on sale).
However, my first degree was in Anatomy with distinction, and we used to use ultrahighspeed centrifuges to separate out eukaryotic cell cultures that were still quite reproductively viable after taking the equivalent of tens or hundreds of gravities.
If by "advanced eukaryotes" you're referring to multicellular organisms (all known multicellular organisms with organ differentiation are eukaryotes, not prokaryotes such as bacteria and archeobacteria), then they will be able to handle gravities of at least Jovian-mass planets without having to use unusual structural materials.
Bone is pretty resilient due to the fact that it's a composite of protein and mineral. Chitin isn't so lousy either, and it's possible that a Terrestrial Jovian-mass planet may have life that goes directly from the sea to the sky after using buoyancy organs evolved for rapid depth change underwater to colonize the atmosphere.
However, all known extrasolar planets detected in the Jovian-mass range have been considered as being gas giants just because we don't have any evidence that any planets that big *aren't* gas giants since every known planet orbiting Sol more massive than Earth *is* a gas giant and not a superterrestrial.
Even for the gas giants, there's a hell of a lot of mass and energy available in their upper atmospheres to allow for large buoyant multicellular organisms.
As recently as thirty years ago, we didn't realize most life on Earth was anaerobic bacteria living miles below the surface - and that's where most of the biomass appears to be, as well.
Life is astonishingly resilient, even the carbon based RNA/DNA stuff we find locally. Take for example the complex multicellular multispecies "black gusher" communities found around deep ocean volcanic vents (at pressures well above the upper atmosphere of Jupiter), or the archeobacteria found in volcanic hot springs.
And tidally warmed moons such as Jupiter's Europa may make the "habitable zones" around stars much larger than strictly trying to spot planets. Jupiter itself gives off more heat than it receives from the Sun, thanks to gravitational heating and radioactive decay.
Finally, although the innermost planet in orbit around Sol is in a 3/2 resonance orbit, Mercury was originally thought to be tidally locked around Sol (the same way that the Galilean moons of Jupiter, such as Europa, *are* tidally locked around Jupiter). Even if a Mercury-like planet close to its star might be very hot, it is possible that in the twilight region just past the surface illuminated by the star might be a region just cool enough to retain suitable conditions for life.
I'm not ruling out anything.
MicroSoft(TM): It's not just a bad idea, it's against the law!
The Marcy and Butler spectrograph used iodine absorption cells to help calibrate the Doppler
spectra they took of the parent stars. They can get down to about 3 meters/second accuracy, compared to about 50-100 meters/s with conventional techniques.
It turned out that 3m/s is good enough to start seeing the Doppler wobbles induced by the Jovian planets going around the parent stars. It's then a matter of patiently looking at lots of stars and hoping you'll strike lucky....
Yeah, not only would the tides likely be impressive, you would possibly, depends on whether the moon is tidally locked, have sever tide cycles a day, though each of different magnitudes, and you would probably never get the same pattern twice. Lots of calls for `surfs up' during the day. Mind you, I'ld hate to be the oceanographer (is that the right profession?) in charge of the tide tables:).
Bill - aka taniwha
--
Leave others their otherness. -- Aratak
You're right - there could be a few planets further out in the system that have yet to be detected exerting a wobble on the parent star. But multiple planet systems have already been found - Upsilon Andromedae has three planets going around it (found by Marcy and Butler, I think...) in April this year.
The technique is good for very close in, big planets, but not sensitive enough for Eath-mass planets at Earth-Sun type distances. But there are other techniques in the pipeline, such as nulling interferometry...
I used to laugh at habitable moons in Science Fiction (Example: 'The Forest Moon of Endor'). Sure, you would have a great night sky there, but it couldn't happen! After all, if you use our solar system for a guide, Jovian sized planets just didn't happen that close to their suns. And, even if they did, high levels of radiation from the 'Van Allen' belts of the super-jovian would make any satellites uninhabitable...
But these recent discoveries show this view to be as short-sighted as a redneck's color vision. Clearly such systems exist, even if they are not common. Of course the only planetary systems we can detect with current techonology include such super-jovian planets, so we still don't know if our own planetary system is 'normal' or not. I suppose it will be fun finding out though!
So the scenario I see is this: Super-Jovian planet located somewhere between the equivalent temperature zone of Earth and Mars with a host of puny to Earth sized moons, one of which (located far outside the super-jovian primary's radiation belts) supports oceans and life. If the primary has a set of rings, well, that would be frosting on the cake. Imagine parking with your sweetie and looking up at the night sky!
On the other hand, imagine two hundred foot tides rushing around the 'moon' in sync with its rotation...
Jack
- -
Are you an SF Fan? Are you a Tru-Fan?
The letters stand for "Henry Draper". Draper was an astronomical spectroscopist and one of the early pioneers of astrophysics. The Henry Draper Star Catalog is a listing of about 130,000 field stars down to a visual magnitude of approximately 9.
We're going down, in a spiral to the ground
When someone says life, everyone inmediately thinks it should be humanoids... it isn't necesarily that way...
Well, carbon based life forms don't have to be humanoid--I'm partial to space slugs myself.
At least at the temperatures we like, silicon based life forms are a challenge. While methane (CH4) is reasonably stable at 25C until someone lights a match, the equivalent silicon based compound, silane (SiH4), will spontaneously combust.
For life as we know it, it helps that CO2 is not considerably more stable than other carbon compounds. This isn't the case with silicon--SiO2 is a whole lot more stable than the others.
That leaves you needing a very cold, preferably oxygen free environment. It might be possible, but it's not the way to bet. (Yes, it also spoils the "I'm a doctor, not a bricklayer!" joke in ST-TOS...)
Pete Brooks
HD = Henry Draper
Means the object is listed in the Henry Draper Catalog of celestial objects. Another common
catalog is the Durchmusterung id number which start with letters like BD, CD, CP, etc.
The catalog naming is slightly arbitrary, but at least it makes it easy to look up. More common
names that you might have heard of before are things like NGC-xxxx...
P.S. actually this isn't much different than the whole DNS naming system if you think about it...
There are "top level" names like slashdot.org and stuff underneath like www.slashdot.org...
I believe that the major point to not overlook, in referring to the 'Jupiter-sized' comment, is that each planet may have many moons as does our own little Jupiter here in this Solar System. It is these lower gravitational bodies that life has the best chance (this is based on the 'more like us' scale - hey go with what works right?). Since there are about 5 of these Jupiter sized objects in the habitable zone, and I would guess at least 1 or 2 moons each (why? no idea, but why not) - I would be surprised if there weren't some multi-celled lifeforms out there.
-Kraka40
Why use up perfectly good places for life to evolve when you have much better control of your
:-)
.. the first time I previewed this post before submission, I had mispelled "important" in the above sentence as "impotant". How ironic.)
environment on artificial structures that you can make from raw sunlight and loose asteroidal materials?
Sort of like a Dyson Sphere? Sounds neat, but I'd say it's a bit beyond our technological capacity at the moment. Until we get to that level, maybe would should stick to planets until we grow out of our technological adolescence.
We should explore other worlds, but we should live in space where all aspects of our environment would be at our control: gravity, temperature, pressure, topography, atmospheric composition, design, ecology, zoning and most obviously whether we allow those Windows riff-raff on board.
And you forgot the most important one: Sex in near-zero-gee would be lots more fun!
(Heh
We're going down, in a spiral to the ground
I'm an astronomer, and as an astronomer 6 new planets are not interesting at all. A lot of astronomers do this kind of thing because it makes good headlines and keeps the funding rolling in.
OK I'll agree it has to be done, and I'll agree that finding extrasolar planets will lead to good science, but simply finding an extrasolar planet is about as exciting as finding a new asteroid.
The first interesting science on a planet was released earlier this month. The first spectrum from the reflection off a planet was taken. Now that is interesting. We can tell what is in the atmosphere from that. We may even find some complex molecules.
That is science, and it is so much more interesting that finding 6 new planet sized gravity wells orbiting stars.
In addition to the discovery of six new planets, the researchers gathered new data on four known planets, whose orbits they had previously studied. Two of them showed long-term trends in their orbits indicating the presence of a companion, which could be an additional planet. These findings are significant because previously only one other system of multiple planets, around the star Upsilon Andromedae, had been identified outside our solar system.
This is so new to us, I don't think i've really seen any work on star study to determine if there are longer period planets. For instance, the one confirmed via the brightness method two weeks back had a period of 3.3 days. Put in their local terms, one of their YEARS is 3.3 of our DAYS. To accurately get something with a period on the order of one of our years or more, a longer study period is needed. (this isn't quite true according to nyquist, but increased samples give increased accuracy) Try getting all that telescope time if you're a lowly grad student with no nearby observatory and meager funding! (especially Keck!)
You can see the NASA press release regarding this at ftp://ftp.hq.nasa.gov/pub/pa o/pressrel/1999/99-140.txt
[humour]Maybe we can all hook up our old satellite tv dishes like Charlie Sheen and have a big distributed star observing effort in a radio telescope version of the SETI stuff! ;-)[/humour]
Demonstrant's Open Source Tools
why don't we save life here on earth before we go looking for it in the reaches of space?
:-) It really is News for Nerds. It's in the nature of humankind to study the universe and make observations about it. We've got an inborn curiosity that we're powerless to do anything about. What we're finding is that planets are really not all that special; that they exist in abundance outside of our own planetary system. Now this was pretty much well-established before these findings were published, but the news of six new planets of this nature just further confirms it.
Why can't we do both?
Why do we have to pick and choose?
Why is the space program, and astronomical research of any kind, the favorite whipping boy of folks who claim to want to eliminate government waste? (This latest discovery comes out of academia, by the way.) While I can't comment on waste within the governments of other countries, some of the more lavish expenditures of the United States government are almost legendary. This is the same government that spends millions of dollars buying boats and airplanes that the military doesn't even want. Hundreds of thousands of dollars worth of US taxpayer money went out to study cow farts. And don't even get me started on the six hundred dollar toilet seats.
And it's the space program people complain about?
Look, I'm all for trimming government waste, but the space program is a veritable island in a sea of pork. It's almost a cliche to present a list of new technologies that sprung up as a result of the space program, so I won't do it, but I will offer one opinion about news of this nature:
It's just fucking cool.
So yes, by all means, let's work to solve the problems that we face here at home. But I don't think it's a "this-or-that" situation. We can have our cake and eat it too.
We're going down, in a spiral to the ground
NASA's "Mars Polar Lander" touches down this Friday (December 3) at 3:37 pm EST. Shortly before that it'll be releasing the two "Deep Space 2" probes to bury deeper into Mars' surface - both will be looking for water and organics, signs of life, and in the most promising part of Mars yet - the south polar area. Newsweek has an excellent cover story on this this week (by Sharon Begley, whose science reporting I greatly respect). Aside from Europa, Mars really is the mostly likely place for life in our solar system. Perhaps more likely than Europa given that Mars clearly had a liquid water ocean early in its history. The next few years should be VERY interesting in the search for extraterrestrial life!
Energy: time to change the picture.
To work, a lung must be able to inflate. In the case of premature infants, the neonate's lungs will tend to stick together, in part because the infant has not been able to produce surfactant (which keeps lung tissuues from sticking together.)
In the case of the Abyss, the extreme pressure at the bottom of the ocean will cause a lungs to collapse, if the incoming gas pressure is not high enough. The problem one gets is that oxygen and nitrogen can be toxic at high pressure. Theoretically, if a liquid, such as a perflourocarbon, could substitute for the carrier gas (He, N, etc), high pressure diving could be made more practical.
In neither case does one actually breathe liquid in place of oxygen. The liquid just carries the oxygen. Perflourocarbons can theoretically substitute for red blood cells--a person with perflourocarbon blood would still need oxygen.
BTW, for those who plan to do deep diving, perflourocyclohexane has its share of problems. But, there are thousands of possible perflourcarbons to choose from. I would suggest doing a search in the scientific literature. You might start with Leland Clark, who has written dozens of papers on the subject.
Hydrogen isn't explosive on its own - it's quite stable. The problem is oxygen, not hydrogen - having free oxygen in our atmosphere is highly unusual (at least Earth is the only body in our solar system with it), and finding free oxygen in the atmosphere of another planet is considered one of the surest indicators of life. Oxygen's reactivity is what makes matches and burning in general so hazardous here on Earth.
Energy: time to change the picture.
At most, one of these planets might be a double-planet system, each approximately half the total mass detected from the star wobble (i.e. they'd still be Jupiter-class). Three or more objects just don't maintain long-term stable orbits unless the third, fourth, etc. objects have insignificant masses compared to the first two.
The most likely configuration, based on known objects in the Solar System and planet-formation theory, is a single planet with moons (if any) far smaller than itself. Luna and Charon are anomalously large compared to Earth and Pluto, and their mass ratios are 80:1 and 10:1 -- 1000-1 seems to be more typical.
/.
/. If the government wants us to respect the law, it should set a better example.
They're basically pulling this stuff square out of their arse.
:-)
1. They can't actually see the things, just get info on distance from the "wobble" effect.
2. Not being able to see them, they can't get any kind of spectroscopic data to make a guess at atmosphere.
3. Without an idea of the atmosphere, there's no chance in hell of guessing surface temperature. Period.
The so-called "habitable zone" is based entirely on distance from the star in question (and the star details, of course). By that measure, the Earth is in the habitable zone (would always be too cold, the atmosphere traps the heat coming in).
That Steven Vogt guy who says one planet is around 108 degrees is completely full of it. It may be that if it's airless, but atmosphere plays a huge role in temperature.
Also, pressure plays a role in what point water becomes liquid or not. Not everything is about temperature.
BTW, if it's airless, there's no liquid water there anyway, having boiled away into space.
---
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
Precisely because it *is* so 'non-essential'. Past cultures that have 'indulged' successfully in astronomy have been some of the most civilized and successful cultures ever; the Mayans, the Greeks, etc.
Not to mention the fact that evidence points strongly at a cataclysmic meteor impact ages ago, leading to mass extinctions, and the likelihood is that another will follow. No one can say when, but no time like the present to get crackin', I say.
The more we focus upwards and outwards, the less significant our personal differences become.
-kent
**>>BELCH