Slashdot Mirror
42 Worlds in 32 Days
Odie writes: "Since the first discovery of a planet
around another star in 1995, some 60+ planetary systems have been
discovered. That's about one every two
month, most of them uninhabitable Jupiter-sized heavyweights. Not much
statistics to put in the
Drake equation. Recently though,
the OGLE team has come up with more than 42 new
candidates. Nice in itself, but
what is spectacular is that they spent only 32 days finding them! At that rate COROT
should soon find plenty of worlds to explore for you budding Starfleet sailors!
"
Come on, need I say more?
Why? Because it's much easier to see Jupiter then it is Earth. Stands to reason.
On the whole, I find that I prefer Slashdot posts to twitter ones because I don't get limited to 140 chars before
We need to get all the stars that have large planets identified as such, and hopefully all of the large planets in such solar systems. Then as our equipment gets better we'll be able to focus on even smaller changes, which will allow us to pick up earth sized planets or smaller.
Also of interest are planets in habitable zones, even large ones. Moons around larger planets could work as well as earth does in the right orbit. Of course, being in such close proximity to a massive planet could present other problems, as massive bodies are more likely to attract other significantly sized rocks, as well as a LOT of radiation if there is a significant magnetic field.
-Restil
Play with my webcams and lights here
Sometimes I really wish we'd spend more money and effort into discovery the deeper ocean. So far there's been less than 5% of the ocean being explored.
When we run out of hospitable land on earth, the best option wouldn't be moon, mars, or any of these exotic planets. It would probably be the vast ocean on earth itself, either afloat or submerge.
Recent discovery on the ocean floor has revealed a host of other life system unsupported by sun light. It is truely amazing. Yet despite spending 13 billion on NASA budget every year, we only have 3 deep sea subs that can venture into the deep..
geek page at KY speaks
I'm in no way a scientist, hell, I'm a Comm. Studies major, i have had a lot of biology classes, so i'm not totally ignorant either. However, it just seems that if we're really looking for life on other planets/celestial bodies, we need to quit thinking so close-mindedly.
Let's say, for argument's sake, that life evolved much the way some scientists say it did, the whole Darwinian macroEvolution of the many species. What does that teach us when trying to look for other signs of life out there? well, i can tell you it definitely DOES NOT mean that we need to look for other earth-like planets with water and it DOES NOT mean we should say "well, there is an abundance of molecules that could form into DNA" or the presence of carbon means anything.
What we need to look at is the *effects* of otherworldly life, and i'm not talking about the "face of Mars"...i'm talking about other signs, real signs of unnatural form/structure in space. We need to quit anthropomorphizing possible alien life and we need to quit looking for life "as we know it."
Even in a time when new terrestrial life forms are being found in places where these educated scientists said no life could ever exist (undersea thermal vents, etc), the science community tends to want to look like life like us (not human, DNA/carbon based life).
As far as we know, we're the exception, and there are interstellar races 10^6 times larger than we are that exist in the fusion reactors inside stars. I'm citing an extreme example, but my point is this: If there was life so extreme, how would we ever notice them? How would we ever contact them? With radio signals embedded with decodable messages? You could broadcast a voice talking over FM radio into space, and when it reaches an alien race, they never notice it because either they've moved so far past that technology or never had the need to use radio-type waves for communication purposes.
IMHO, the only point in looking for "inhabitable" planets is for future colonization. All else is simply pointless.
damn, that was my last $0.02...
Beer, now there's a temporary solution -- Homer Jay S.
Yes, that's a great idea. And so if the deep
is still virgin by the time that we've *really*
screwed everything up, why shouldn't it join
the rest of the planet? At least there's
nothing to wipe out on the moon. Well, there'd be one thing if we ever got off our collective
duffs and did something, ourselves.
And here's a news flash, the few billion
spent on NASA is *nothing*, it's barely
worth mentioning. It compares not to the rest
of the budget, you want to know why congressmen
and everybody focuses on it? Because it's high
profile (because it works). It's easy to say,
NASA, bof what have they ever done for me?
I didn't fly to the moon, they're useless.
The returns on investments in space far
outweigh what we've put into it.
Just think about (and these are only the most obvious):
Telecom, sneakers, jeeps, Tang, alloys and
other materials, pretty pictures for your desktop,
and on and on and on.
Not to say that NASA couldn't some things better,
but that's a horse of a different color. And
I'm not saying we shouldn't explore the deep
oceans either, but we should be extremely osking
careful when we do. But to compare deep sea
to space is blasphemy.
Were that I say, pancakes?
They were detecting these planets by watching for "transits", in other words eclipses. If you look at a star&planet from a random direction there is a VERY small chance that it will happen to line up exactly right to see an eclipse. I would estimate the chances as several thousand to one.
With further analysis they can get a pretty solid multiplier for the number of unseen planets. These other planets must exist, and you now know something about them. In a sense they have indirectly measured many thousands of planets.
Even without seeing them, the indirect knowledge about the other planets has scientific weight. This indirect measurement will be very useful in our understanding of other solar systems, how they are structured, and how they form.
The scientific value of the 42 measurements carries a large multiplier.
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
It's probably because they have yet to be properly explained, while still accounting for the very explosive solar transition that pulsars are believed to form under. He may have another reason, but the basic idea behind this is that the planets should be toasted in the initial creation of the pulsar. Yet, there they are, and they were discovered way back in 1990 or 91.
josh
gigantino.tv - Heavy but weighs nothing.
We are alone. There may only be a handful of habitable planets in the entire Universe.
So think now, of all near, discovered earth-like planets, how many had an unusual, rare collision with another planet of similar size of our Moon ? !
Do the math! WE ARE ALONE !
The best part about it is that it's a cheap solution -- you just add this weird "cat's-eye" type lens onto a normal telescope. This deflects all the light from the center of the frame away, but allows the light on the side of from to come in. This way, the light of the much brighter nearby star won't block out the smaller planet.
The Discovery article was pretty cool. This is the only equivalent I could find online.. Unfortunately it doesn't go into as much detail.
http://www.princeton.edu/pr/pwb/01/0416/6a.shtml
The radius of the milky way is 100,000 light years with an average thickness of 10,000 light years. There is a 30,000 light year thick bulge at the center of the galaxy where many of the hundred billion stars in this galaxy reside. I'm basing this on this page. at this rate of planetary discovery it seems that a high rate of stars may have jovian size gas giants. Until we have more data though it's a difficult number to determine. However jovian planets are largely hydrogen and helium gas. Potentially they could form anywhere a star could, while earth type planetoids would require enough dense matter to form into solid planets.
these planets also have to form within the stars habitable zone. Still with roughly 4 billion cubic light years of milky way galaxy on average there are 25 stars within one cubic light year of each other. Meanwhile we're at a density rate of about 0.1 stars per cubic light year, meaning that even with an optimistic calcualtion the nearest earth like planet would be 50 light years. The nearest earth like planet in a habitable zone 150 light years away the nearest life inhabited earth like word 450 light years away and the nearest civilization some 1,350 light years away. That means SETI is a worth while project, but that unless we defy physics by coming up with a FTL drive there isn't any way we're meeting any alien races.
Note these are Highly optimistic numbers and assume that every star system with as many jovian planets as ours would have as many solid planetoids like our system.
https://www.gnu.org/philosophy/free-sw.html
This probably brings up the big ugly question of intellectual property. Does the person who found a new planet get to claim it, or are all of the planets found by a particular technique the property of the person who designed the technique? I am sure lawyers will spend millions of tax dollars deciding such important questions.
Its amazing that anyone is surprised by the "discovery" of planets around other stars.
Direct obersrervation of these bodies is interesting and exiting, but only because we are finally getting to see directly what most intelligent people already knew was there with absolute certainty, and not because its actually sometheing unexpected.
It would be utterly incredible if there were NO planetary bodies orbiting other stars; now THAT would be a scoop.
The fact that they are finding them so quickly is merely a funciton of having better equipment. You would expect to find more planets with better telescopes, and when they finally put a very big telescope on the dark side of the moon, or launch some other new excellent device, all the smaller bodies will suddely resolve out of the glare.
What I find truely beautiful is the range of unimagined objects that the hubble keeps uncovering week upon week. Like this stuff.
ATH0 Bitcoin: 1DnwFLXczVZV8kLJbMYoheUrpqHesjxrSi
Hey! A Chtorr reference! Which of these 42 worlds do ya think is the Chtorr homeworld? When's the next novel coming out? The last one I read was about the airship expedition over the Amazon, ending with Jim and Liz getting medi-vaced out of the rain forest...to be continued....
And who gets to name the multi-tentacled 4 eyed gray puddings that live on them??? Just wait until filthy rich folks are allowed to launch ships and homestead planets (why it's the planet of BillGatus!) Will the future founders of these planets get to pick their own forms of government? Will they quickly evolve so differently (both physically and culterally) that they won't even be recognizeable?
I Am My Own Worst Enemy
Too bad that Star Trek had the following explanations for any technical questions.
"How does the warp drive work?"
"Very well, thank you."
"How does the transporter work?"
"It recalibrates the photonic field generators in the alternative energy matrix to recapitulate the baryonic flux."
Omnia vestra castrorum habetur nobis.
For example, the Earth was larger but due to a rare collision the Moon was split off.
There is some merit in this view.
However, it is not certain that tides were needed for the formation of life. Hydrothermal vents are a much more likely site for the origin of life, and unless you're on a world like Europa don't have much to do with tides. And don't forget the conquest of the land happened independently by insects, plants and amphibians. Can't be that hard now can it?
The moon does assist in producing some interesting rhythms and aiding nocturnal animals. But I don't see why there can't be local replacements for these or even if they are needed.
Another thing to remember all these planet surveys are sensitive to planets that strongly perturbe the star. That is, BIG planets close in ... or big planets in higly elliptic orbits etc. Not really conducive to finding earth like planets. Don't forget that the number of stars within a given distance of the Earth is about proportional to the cube of the distance (ignoring clusters etc) so within 100 light years there are 125 times as many stars are there within 20 light years (very approximately of course). So of all these thousands of nearby stars they have found 60 - 100 extreme systems. It proves that planets exist for sure, but we'll have to wait for the next generation of star searchers with optical searches for planets using spacebourne multiple telescope systems or whatever they're called.
Pete
Bitter and proud of it.
I was intrigued to hear about the strong radiation that blankets Jupiter's moons. Those would have been the closest place to look for life outside of earth. I forget the reference, but it turned out that Jupiter's massive auroras create too severe of a radiation field for life to exist, at least as we know it. But who knows, maybe some form of life has adapted to extreme radiation. After all, some alien could say the same about earth, until he saw that the earthlings skin tans in the sun :)
... that none of the trolls have made an OGLE team / heavenly bodies / Aria Giovanni post yet.
Y2K Compliant since the late 1890s
at this rate of planetary discovery it seems that a high rate of stars may have jovian size gas giants. Until we have more data though it's a difficult number to determine. However jovian planets are largely hydrogen and helium gas. Potentially they could form anywhere a star could, while earth type planetoids would require enough dense matter to form into solid planets.
Even systems with gas giants hogging the habitable zone have potential for life. With gas giants much larger than Jupiter seeming to be the norm, I'd assume we can expect that the giants would have larger moons better fit to life. So it doesn't matter where those solid objects form; as long as they are caught by a gas giant in the right orbit and happen to have the right composition, life could still arise in that system.
I'd imagine that any new civilization on one of these moons would take less time to inhabit the many moons of a gas giant than we are taking to explore our mere one. So many fascinating spacial wonders would be right up close to entice intelligent beings to explore them. How beautiful it would be to have a Jupiter taking up most of the sky!
Remember "Bring 'em on"? *sigh
My original reply was more of enthusiasm then accuracy however, I do stand corrected. You are correct when it comes to using Doppler efects to measure bodies in motion, particularly 2 bodies in orbit around each other. I realised later that I had used the wrong term to decribe what was in my minds eye. The term I should have used, was Astrometry.
Astrometry, is used to determine the proper motion of a star, using other stars as reference points. If a body is revolving around a star then the body will affect the circular motion of the star. As one measures the stars linear motion, it will be found that the motion is not in a straight line, but rather in a wobbly line due to the presence of a planet or planets revolving around the star. This situation is similar to observing a person spinning a shotput around his or her body. The person shows a wobbling type motion due to the heavy load that is being rotated about his or her body. The person represents the star while the shotput represents a planet. In addition, the person can move from point A to point B while the shotput is revolving. Therefore, there are two motions, the wobbly motion caused by the rotation of the shotput, and the linear motion caused by the movement of the person. If the person was not rotating a shotput and simply walking, then the only motion observed would be the distance from point A to point B, and no wobble in the motion would occur. This, of course, presupposes that the person is sober. In like manner, if one were to observe the proper motion of a star without any planets revolving about it, then the distance the star moves from point A to point B would not reflect a wobbling motion, the motion would be in a straight line.
Radial velocity, which is measured by the doppler effect (lines in the stars spectrum) takes into account the line-of-sight velocity; i.e. the velocity of which a star is moving towards or away from us. If the light from the star is moving towards us then the spectrum of the star will be shifted to the blue portion of the spectrum (blueshift) and the velocity would be negative. If, on the other hand, the star is moving away from us then the spectrum of the star will be shifted to the red portion of the spectrum (redshift) and the velocity will be positive. By observing the spectral shift one can determine the rate at which the star is moving.
How does this relate to the detection of planetary bodies revolving around stars? If a planet or planets revolve around a star then the motion of the star will be affected. According to Alan Boss, writing in Physics Today, if a star is orbiting around the center mass of a system, then it suggests a planetary body or bodies revolving about it. More to the point, if the above is true then there would be a periodic shift in the doppler velocity. This is the star's spectrum would exhibit a shift to the red and then to the blue, and then to the red, periodically. In other words, the effect of planetary bodies around a star will affect the radial velocity of the star so that it would be moving towards us and then away from us, and continue to repeat that pattern. It should be noted that the perturbation or doppler velocity shift is very small, and therefore, extremely difficult to detect.
Many of the ensuing discoveries rely heavily upon radial velocity techniques. Highly specialized spectrographs, that can detect tiny doppler-induced wavelength shifts in a star's spectra are used to calculate the radial velocities. However, it will be of no surprise to note that the planets that were discovered using this technique are large and/or are in tight orbits, because this technique disposes itself to that type of finding.
The direct imaging method is based on the fact that planets reflect the stars' light. Planets do not give off any light of their own. For example, the various planets we see in the night sky are a result of the sun's light reflecting from them. Likewise, planets around other suns would also reflect the light of their suns. This method is used in order to determine reflected light from an extrasolar planet. It is obvious that only extremely large planets may be detected using this method. The major problem with this technique is that the star is much brighter than the planet it illuminates, and can tend to obfuscate it.
Photometry can be used to detect a change in the brightness of a star, as in the case when a planet occults a star. On Earth we can observe this during a solar eclipse. That is, our Earth occults our Sun during an eclipse. As an extrasolar planet revolves about its star, it will pass between its star and the line of sight as seen from the Earth. A change in the brightness of the star due to this transit would then suggest a planetary body.
Earth sized bodies would indeed be almost invisible to Dopler shift searches, but developments are are already well underway to correct this problem. I have submitted a post on this subject,mostly consisting of links, but I am still waiting for it to be authorized. If it should be declined, I will write something up on it in a reply to this post for the sake of discussion.
Actually, I've been waiting for the next book for quite a while now.
I just assumed the author had died before finishing the series.
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
Thanks, but the topic isn't using telescopes (which generally don't utilize lenses anymore), but lensing. In this context, it refers to the bending of light by massive objects. Planet searches are underway using this technique, but none have been successful.
As I said earlier, I don't expect we'll ever find Earths with Doppler techniques. The spectral lines in the stars are broadened by the activity on the stellar surfaces by more than the amount of the shifts due to planets. This makes it extraordinarily difficult to pick out the planet's effects.
Astrometery probably won't help much, either, as long as the point-spread function of the telescopes blurs out the star's light by well more than the amount that the stars move. Even without that effect, it's tricky. I spent a summer doing astrometry. You have to do it differentially (relative to nearby objects) rather than absolutely (position on the sky) because exact positions are too imprecise. But even that was tough, given all of the instrumental and atmospheric effects.
The current method is only suitable for huge (multiple Jupiter size) and fast planets. Thats because it uses doppler shifts to look for slight gravity frequency shifts from stars. The shift must be fast and big.
Space-based methods promise more sensitivity and proposals are in the works.
An alternative method is the light curve method that looks for planetary eclipses of edge-on systems. This has only generated a couple candidates. The already-approved space mission Kuiper will watch the same patch of sky of five years continuously for rare planetary eclipses. It has a 350 megapixel imaging array (42 x 8 megapixals). This could detect earth-size planets.
I believe he's talking about tides.
On a planet with only solar tides, the intertidal region where all the interesting sea-land evolution is happening is much smaller. I don't think it's necessarily *too* small, but it might take longer.
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E_NOSIG