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Space Science

Planetary System Similar to Sol 379

Posted by michael
from the new-places-to-go-to-war-against dept.
sgtwilko writes "The BBC News site has an article about how astronomers have found several new planets including some that have a similar distribution to our own Solar System. They are finding planetary systems that are more and more like the one in which the Earth resides. It's only a matter of time until the Terrestrial Planet Finder program gets going and finds another Earth." There's another story on space.com. Update: 06/13 21:51 GMT by M : Space News and Wired have stories as well, with spiffy graphics and artists' renderings and so on.
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Planetary System Similar to Sol

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  • WOOHOO! (Score:4, Funny)

    by Bob McCown (8411) on Thursday June 13, 2002 @02:25PM (#3696101)
    First we find the big planets

    Then we find the small planets

    Then we find the ones with intelligent life

    Then we communicate

    Then...

    Alien Pr0n!

    • Re:WOOHOO! (Score:5, Funny)

      by daeley (126313) on Thursday June 13, 2002 @02:50PM (#3696307) Homepage
      Jack Handey had it right:

      "I don't think I'm alone when I say I'd like to see more and more planets fall under the ruthless domination of our solar system."

      "Whether they find a life there or not, I think Jupiter should be called an enemy planet."

      "I can picture in my mind a world without war, a world without hate. And I can picture us attacking that world, because they'd never expect it."
      • Re:WOOHOO! (Score:2, Funny)

        by unicron (20286)
        Nothing will EVER be funnier than:

        "Often, children will ask me where does rain come from, and I reply 'God is crying' and if they ask 'why is God crying' I always say 'I don't know, but it's probably something you did'"
    • Re:WOOHOO! (Score:2, Funny)

      by Ztream (584474)
      That's about time, I've already seen all the pr0n *this* world has to offer.
    • Re:WOOHOO! (Score:2, Funny)

      by Dimensio (311070)
      Then we find the ones with intelligent life

      I think that the sticking point will be here. I'm not yet convinced that even one such planet exists within the entire universe.
    • Then...

      Alien Pr0n!


      Why do I need to find another planet for that? I can think of several people in Texas that could pose for that...

      have you checked the newsgroups yet?
      • Re:WOOHOO! (Score:2, Funny)

        by EverDense (575518)
        news://alt.binaries.erotica.alien news://alt.binaries.erotica.alien.tentacles news://alt.binaries.erotica.alien.bugeyed news://alt.binaries.erotica.alien.greys news://alt.binaries.erotica.alien.yoda news://alt.binaries.erotica.alien.yoda.sucks
        • Re:WOOHOO! (Score:2, Funny)

          by Anonymous Coward
          you have way too mmuch time on your other hand.
    • Zapp: "Captain's Journal. Stardate...uh..."
      Kif: *sigh* "April 13th."
      Zapp: "April 13.2! We have failed to uphold Brannigan's Law. However, I did make it with a hot alien babe. And in the end, is that not what man has dreamt of since first he looked up at the stars? Kif, I'm asking you a question."
      Kif: *sigh*

      (audio version [gotfuturama.com])

  • by bwohlgemuth (182897) <bwohlgemuth@@@gmail...com> on Thursday June 13, 2002 @02:27PM (#3696116) Homepage
    The system also has a slightly smaller neighbor which whips around every 14.5 days. My guess is the tidal forces of these two planets would eventually rip anything in between to shreds.

    Yes, TPF will be a nice box to have. However, I wouldn't plan on the longevity of HST since it will be located at one of the LaGrange points just outside earth orbit.

    Brian
    • by NoBeardPete (459617) on Thursday June 13, 2002 @02:52PM (#3696326)

      The astronomers said that an Earthlike planet _could_ survive in an orbit between the two large ones. Given a choice between your guess that it would get ripped to shreds, and the opinions of professional astronomers who've studied this specific solar system, and concluded that an Earthlike planet could be there, I'm going to side with the astronomers.

      • Of course, the most accepted model for the "hot Jupiters" has them forming in the outer system and migrating inward, disrupting the orbits of any intervening planets. So even though a planet could orbit between them in theory, odds are that any such that existed were tossed into less earthlike orbits (or ejected from the system entirely) as the hot-Jupiter-to-be spiralled inward.
  • by iforgotmyfirstlogon (468382) on Thursday June 13, 2002 @02:28PM (#3696128) Homepage
    It is all just a hoax. As it turns out, a group of rival scientists went up into space and just put a REALLLY big mirror up there.

    - Freed
  • by Dark Nexus (172808) on Thursday June 13, 2002 @02:29PM (#3696135)
    Okay, so the planet 3-3.5 times the size of Jupiter, at NEAR the same orbit as Jupiter....

    But that planet right near the star that's just a bit smaller than Jupiter is a BIG difference.

    But hey, it's a start, and doesn't mean that there AREN'T planets geologically similar to Earth there.

    Guess we might find out soon.
    • Also on this note... (Score:3, Interesting)

      by Dark Nexus (172808)
      A quote from the CNN article [cnn.com] (which seems to be a bit more fleshed out) I didn't see in either of the ones listed at the top:

      "We haven't found an exact solar system analog, which would have a circular orbit and a mass closer to that of Jupiter. But this shows we are getting close," said Paul Butler, another member of the planet-hunting team.

      But the orbit of the Jupiter-like planet is stable enough to foster a benign, life-friendly environment in the inner solar orbit, Fischer said.
  • by macsox (236590) on Thursday June 13, 2002 @02:30PM (#3696141) Journal
    i don't get the thrust of the article focusing on finding earth-sized planets. is there some theory that necessitates a planet be our size to foster life? if so, why?

    (here comes the (-1, Ignorant). bring it on.)
    • "i don't get the thrust of the article focusing on finding earth-sized planets. is there some theory that necessitates a planet be our size to foster life? if so, why?"

      I'm taking a page from Spock here:

      Are we humans so arrogant as to assume that life can only be found on planets that closely resemble our own? Why can't life exist in forms completely unimagined by us on red-hot planets close to suns or enormous gas plants? And if we ever saw that sort of life, would we recognise it even if it was staring us in the face?

      • Who is to say that this red-hot gas being in not arrogant as well? If they do exist, and if they are looking for other life, they are presumably looking for life that resembles them, this begs the question would they recognize us as life? Or are we just conglomerations of biological processes. The reason that we are arrogant is that we were created in the image of our creator, and we thus have the very notion that all life must resemble the life we see on earth ingrained in our very being. There is in fact life other than ours in the universe, it's just in a different realm, and it does not have our form. There is also a different life available for us to live by, that replaces our own, but that is a different subject all together.
      • Human Arrogance (Score:3, Interesting)

        by hokanomono (530164)

        On the other hand, my uncle said:

        The idea that there has to be life somewhere else in the universe too, is just based on the image that life is something superior, something special that the universe was just made for. As if it was not fair that only the earth carries life. If we leave our egocentric view and accept that the universe does not care about life, the belief in extraterrestrial life is absurd.

        I completely agree with both, Spock and my uncle.

        • Re:Human Arrogance (Score:2, Insightful)

          by tgibbs (83782)
          Actually, your uncle has it exactly backwards. The idea that there is likely be life somewhere else in the universe is based on the idea that life is something rather ordinary, and therefore should not be terribly uncommon. If we leave aside our egocentric view that we are something special, then the belief in the absence of extraterrestrial life is absurd.
          • No, he actually has it the right way forward. If you view life as an abberation (based on how absurdly complicated and extraordinarily delicate life is), not the main point of the universe, then you wouldn't expect to see that abberation frequently at all. In point of fact, given how exacting the requirements of active life are (it is true that inactive bacteria can survive quite a lot, but they don't do anything while they're surviving, i.e. they don't reproduce while on the outside of a space shuttle), if the universe is not predisposed to create life, while it's already quite a wonder to think that it did it at all, it's even more absurd to think that it would do it again.

            • Re:Human Arrogance (Score:3, Insightful)

              by junkgrep (266550)
              A general rule here is that, in the abscence of a good causal model predicting why there would be more examples, you need at least two examples of something before you can conclude that it is likely that there are more than the one example you currently have. That's how you establish it as a possible reproducible pattern, rather than a one-off fluke. We currently only have one example of life appearing in the universe: here. So we really can't say too much yet about the odds of it appearing elsewhere.
      • Actually, that's part of the point. If we don't have a clue what it looks like, we might not recognize it. If we look for what we're familiar with, we're more likely to recognize it.

        Just because we're looking for situations similar to ours doesn't mean we'll find it. It also doesn't mean they're *not* looking for different situations (say, Mars or Europa).
      • I think that any good scientist (astonomer or not) will admit that life could take on any number of forms. But of all those forms, which ones are we likely to be able to communicate with? That's really the ulitimate goal, isn't it?

        -B
      • Are we humans so arrogant as to assume that life can only be found on planets that closely resemble our own?

        We know enough about the form of life that exists on Earth to set out some clear parameters for speculation. Other forms of life, if there are any, are so profoundly unknown that there is simply no way to draw any conclusions -- it's like arguing the number of angels that can dance on the head of a pin.

        • it's like arguing the number of angels that can dance on the head of a pin

          Now, now--arguments like that depend wildly on the number of angels that actually show up and are inclined to dance on said pin.

          I think I can skip the research this time and just state as fact that, in all of recorded history, never has there been "not enough room" for one more angel dancing on the head of a pin.
      • And if we ever saw that sort of life, would we recognise it even if it was staring us in the face?

        Maybe not the staring, but once it started gestating in our stomachs and erupting through our abdominal walls, we might. : )

        Or possibly, blowing up our capitals. Or offering to sell us something. Or filing suit against Microsoft for anticomptetive practices. The usual things that get our attention.

    • by bwohlgemuth (182897) <bwohlgemuth@@@gmail...com> on Thursday June 13, 2002 @02:39PM (#3696218) Homepage
      Easy...the word is gravity.

      Smaller planets like Earth with lower gravity wells allow (currently known) life forms to be able to move easily. The best analogy would be the shuttle. Takes a bunch of fuel to move it. If you don't put much cargo it the ship, you need less fuel to take off. However, if you max it out, you not only need fuel to move the bigger mass, but to move the additional fuel as well. Now apply that to animals, either they would be really tiny or really huge.

      Now, if you want to get into the realm of life forms that exist either in a gaseous state or as energy, I'll have to refer you to Mr. Bisson's story in Omni from a while ago [electricstory.com].

      B
      • Gravity isn't such an important factor. If you calculate the surface gravity on Jupiter, you'll find it's only 25 m/sec^2, or about 2.5 G's. Humans can tolerate that over short periods, so it's not hard to imagine other organisms evolving in that enviroment.

        The problem on jovian planets is lack of biogenic elements, like carbon, nitrogen and oxygen. Sure, they're present, but they're very dilute thanks to a whopping abundance of hydrogen and helium. So terrestrial-sized planets seem to be the way to go.
        • Wouldn't the hydrogen and helium just float up out of the way?
          • Yes. And the Carbon, Iron, Silicon, and any other heavier element would be left to form a crunchy center. The hydrogen would eventualy float to a certain point where the buoyancy in the atmosphere would be equal to the gravitational pull of the planet.

            Also, it's been hypothesized that any Hydrogen at the center would be under such immense pressure it would change into a metallic state [llnl.gov].

            B
            • Anything in the core (assuming, as most do, that there *is* a core) is under extreme pressure. Not a great place to live.

              The metallic hydrogen is almost certianly there. Something has to be generating that whopping magnetic field. But it's not terribly relevent to the search for life, since hydrogen by itself (metallic or otherwise) doesn't form many interesting compounds.
    • I think that planets larger than a certain size can only be gas giant planets. The temperatures and pressures involved would not support life as we imagine it. Only small planets with an orbit very close to ours will have the ground/water/atmosphere setup that could create life that would look like us.

      IANAAstronomer

      -B
    • There are definatly limits in both directions. Our best guesses about what we need for life include liquid water, and available chemicals such oxygen in the atmosphere (Not O2, that is too reactive and can only be sustained in the atmosphere by the continual release by photosythesing life).

      A small planet would end up like Mars or Mecury, as the gravity wouldn't be sufficent to prevent the atmosphere escaping. On the other hand, a very large planet would have a very high presure at sea level. As water boils at a higher temperature as pressure increases, the higher the pressure the lower the amount of evaporation, and thus this reduces the water cycle. This means less errosion on the continents, which means less minerals in the water. Of course the really big planets are all gas giants, which are obviously going to be difficult for life to evolve. So definatly we need a planet which isn't 'too big', and isn't 'too small'. What those limits are, we can't really say until we get some evidence.

    • i don't get the thrust of the article focusing on finding earth-sized planets. is there some theory that necessitates a planet be our size to foster life? if so, why?

      Planets smaller than Earth will tend to lose their atmospheres over time (e.g. Mars, Mercury).

      Planets larger than Earth will tend to have super-thick atmospheres with very hostile environments (e.g. the smaller gas giants, and Venus). Notice Venus in this list - an Earth-sized planet has a gravity well deep enough to hold an inhospitably thick atmosphere. Only some quirks of Earth's formation and evolution (mainly the presence of the moon) give us an atmosphere thin enough to let our type of climate and our type of life exist.

      Life could exist deep underground in a much wider range of planets, but this would be microbes and not much else.

      Life could potentially exist in oceans under the frozen crust of smaller worlds (e.g. Europa), but would likely be less interesting than life on Earth-like worlds, due to a much smaller energy throughput. These worlds would also have to have a substantial source of heat (either radioactive, like Earth's, or tidal, from being a satellite of a larger planet) to avoid freezing solid. Larger worlds will probably have enough geothermal energy to churn up their oceans, making stable life-bearing layers less likely.

      So, Earth-like planets do seem to be the best place to look for non-microbal life :).
      • Only some quirks of Earth's formation and evolution (mainly the presence of the moon) give us an atmosphere thin enough to let our type of climate and our type of life exist.

        Interesting. Could you elaborate on this? (which quirks? how does the moon fit in to this?
    • Basically...yes, there are theories that say life can only exist in similar conditions to our own. We look for a certain habitable range where life could conceivably exist. Which doesn't mean there couldn't be life on a completely different type of planet, but how would we ever know it's there? We haven't even made it to mars, much less some gas giant in a completely different solar system.

      Also keep in mind that according to our planetary creation theories, any planet that large isn't going to be a terrestrial planet. No Rocks, no oceans(unless you count oceans of liquid hydrogen that probably form from the enormous pressure). There's just no way life in any way similar to us could exist in such an environment. Really, right now we're just trying to see if life like us *could* exist elsewhere, not that it actually does.

      And also, until we find other terrestrial planets, we have no way of proving that our planetary creation theories hold water. Sure, we think there should be earth-like planets out there, but we just have no proof. These discoveries are very encouraging when you remember that until very recently, we hadn't found *any* other planets out there. The more we learn about other systems, the more we can correct our vision of the universe as a whole.
    • Finding life, at least the class of things that we'd immediately identify as "life", requires several things: a chemical environment that is reactive, but not TOO reactive: a physical environment that is generally between the freezing and boiling point of the primary working fluid of the life-forms, an energy environment with sufficient energy influx to beat radiation losses, but not so much as to speed up most of the available chemical reactions.

      That gives us two things to look for. It tells us how far from a star to look (for the temperature and energy variables), and THAT gives us the likely type of planet to find in that region. From what we know of the physics of planetary formation, those planets would tend to be small and rocky, with the likely working fluid being water.

      With a planet with aqueous water, the likely atmosphere would include some oxygen, but too much or too little would tend to work itself out over time (too much, and you tend to support a LOT of combustion, which would take up the excess oxygen. Low oxygen environments are thought to be similar to that in which life developed here on Earth. . . )

      In a long and possibly too-technical explanation, that's why we look for "Earth-like" planets when we look for life. . .

    • Ok, ignoring the "our theories say" bit on finding life, let's look at it from another (perhaps even more improbable) angle.

      If we want to terraform other worlds, our best bets are to find similar worlds to do that with. When you're building a house which do you look at first - the flat land that's already cleared or the swamp?

      Even if we were to determine, definitively, that we are the only sapient species within 1000 light years, finding Earth-like planets means we have someplace to go that won't require too much work. Frankly, if we're stuck terraforming gas giants, then screw going elsewhere - let's build a Dyson sphere (or Ringworld, or what have you) here first. It's just about as feasible.
    • Ever notice how all the small planets are rocky and all the large planets are gassy? This is not a coincidence. Jupiter and most likely the rest of the gas giants have solid cores, larger in fact than the earth, but due to their immense mass, they have an extremely dense atmosphere, which could not support life, at least as we know it.

      As for smaller planets, you end up with situations like Mars. Mars has an atmosphere, although it has less than 1% of the air pressure that Earth has. .1% if I remember correctly, but don't quote me on that. The gravity of the planet is insufficent to maintain a signficant atmosphere. Atmosphere "leaks" off into space all the time, even on Earth. This lack of atmosphere creates several problems. First, breathing would be extremely difficult, so life forms that DO exist would have to sustain themselves on very little air. Meteors would also present more of a problem, as they can't burn up as easily.

      Venus has sufficient atmosphere, but its proximity to the sun, as well as the contents of its atmosphere, creates an environment that's too hot for "conventional" life to survive.

      Of course, you also have the issue of habitable zones and their relation to the size of the sun. Consider our solar system as one that works. We're not too close, nor too far away from the sun, and the sun has 10 billion years of life (half of which it has expended already). Say we're looking at a larger star, like a blue giant. The planet could orbit further away and maintain the same temperate zone, but in 10 million years that sun is going to go supernova and any life will have not had enough time to evolve from inception. It took longer than that just for the Earth to cool down.

      Large planets orbiting close to the sun present a problem. The primary concern is how they got there. Chances are good that they didn't form that close to the star, but formed further out then migrated inward to their present positions. If this is the case, its a darn good chance that any planets within the habitable zones will have either collided with the gas giant or been kicked out of the solar system.

      The lack of any gas giants is also a problem. Jupiter does a nice job of attracting and "removing" potential threats to Earth, mostly the very large rocks. Without the gas giants out there to help us out, the Earth would get battered far more frequently than it does. Life can handle a huge hit once every 60 million years or so. Long term evolution would be severely hampered, however, if it happened more frequently.

      A potential alternative to the current solar system is a gas giant located in the habitable zone with a earth sized moon. The moons of Juipter would have a significantly more viable climate if they were orbiting at 1 AU. However, this would present other dificulties, namely tidal lock. The moon would have to be sufficiently close to the planet so it didn't roast any one side for any significant length of time, however, the planet itself would block the light to the moon, so the moon would have one side that was perpetually frozen and the other side that had to endure long days and long nights. And any moon close enough to the planet to orbit quickly enough would have severe tidal problems... think IO.

      So anyway, our best bet... is to find a solar system that resembles ours. At least until we find another model that works. Sorry about the extended rant.

      -Restil

  • by quantaman (517394) on Thursday June 13, 2002 @02:31PM (#3696147)
    They have also found the smallest exoplanet yet. It is only 40 times more massive than Earth.


    The size of the planet isn't really the issue though,
    Detecting Earth-sized planets is probably not possible using current ground-based techniques. That will have to wait for a new generation of satellite observatories, due in the next decade.

    The important part is
    Calculations made by Greg Laughlin of the University of California at Santa Cruz show that an Earth-sized planet could survive in a stable orbit between the two gas giants.


    This of course doesn't mean that we found anything only that when we are able to look for earth-like planets this is our best bet for hitting the jackpot.

    • Calculations made by Greg Laughlin of the University of California at Santa Cruz show that an Earth-sized planet could survive in a stable orbit between the two gas giants.

      The question then is, is it stable enough for one to form, not just survive. Very different questions.
      • I would think that such a planet would probably never get any meteor impacts. What could get past those gas giants? However, look at the perturbations that would be caused by passing that innner gas-giant every year (gas-giant's year) - the planet would have a stable orbit, but HOW stable? And would it be stable enough to maintain a normal climate? Or would they be innundated with alternating hothouse and ice age conditions? And is the inner gas-giant close enough to cause tidal forces (and strong geothermal/volcanic activity?)

        Whatever would evolve on that world would likely be one tough sonofabitch.
    • The important part is
      Calculations made by Greg Laughlin of the University of California at Santa Cruz show that an Earth-sized planet could survive in a stable orbit between the two gas giants.

      This of course doesn't mean that we found anything only that when we are able to look for earth-like planets this is our best bet for hitting the jackpot.

      --

      /me does a double-take..

      Just because it is possible for a frog to survive on a patch of grass dividing a 6 lane highway, does not mean that this is the best place to look for frogs.

      Currently, we are using radar guns to observe speeding tractor-trailers, and speculating that due to the theoretical possibility of frogs living in the adjacent grass, that's where we should focus our efforts.

      If you want to look for frogs, you go to a swamp, marsh or pond. Now, where are equivalent environments for finding Earth-sized planets? And what do we need to find them?
  • by dlb (17444)
    It's slow and full of pop-up ads..
    ----

    A team of astronomers announced today the discovery of the first planet outside our solar system with an orbit similar to Jupiter's, a configuration that has the potential to support an Earth-like planet.

    They also found the least massive world ever detected around another star, a planet just 40 times as heavy as Earth.

    The primary discovery is a gas giant planet that circles a star called 55 Cancri every 13 years, comparable to Jupiter's 11.86-year orbit. The planet is between 3.5 and 5 times as heavy as Jupiter.

    "It's the first extrasolar planet that reminds us of a planet in our solar system," lead researcher Geoffrey Marcy said in an interview with SPACE.com several days prior to the announcement.

    Marcy, of the University of California, Berkeley, said he and colleague Paul Butler, of the Carnegie Institution of Washington, have dreamed of this discovery for 17 years as they compiled data using a technique that many scientists said would never work. The two astronomers, whose team has grown in recent years, also announced 11 other worlds today at a press conference at NASA headquarters, bringing the total of known extrasolar planets to 98.

    Potential for Earth twin

    The new planet orbits 55 Cancri at 5.5 astronomical units (AU). One AU is the distance from Earth to the Sun. Jupiter orbits at 5.2 AU. The same team had already spotted another planet around 55 Cancri, a place slightly less massive than Jupiter. It orbits so close to the star that it makes a complete orbit in just 14.6 days.

    Marcy speculated that the two-planet system could harbor more intriguing worlds, possibly even rocky planets like Earth, known as terrestrials.

    "A Jupiter at five Earth-Sun distance units might serve as the marquee of a planetary theater located within, where terrestrial bit players are racing around on smaller tracks," Marcy said. "We are left to imagine what geophysical and perhaps biological improvisation is taking place inside this planetary playhouse."

    Armed with their new data, Marcy and Butler enlisted theoretician Gregory Laughlin of the University of California, Santa Cruz, to look into whether the 55 Cancri system could also retain an Earth-sized planet in a life-sustaining orbit. Such a region, called a habitable zone, would maintain moderate temperatures suitable to the retention of surface water and the possibility of life.

    Laughlin ran the data through computer models of planet formation. The answer is "yes."

    "We tried a hypothetical configuration of a terrestrial planet in the habitable zone around one AU from the central star and found it very stable," said Laughlin, who also is associated with Lick Observatory. "Just as the other planets in our solar system tug on the Earth and produce a chaotic but bounded orbit, so the planets around 55 Cancri would push and pull an Earth-like planet in a manner that would not cause any collisions or wild orbital variations."

    Marcy and Butler caution, however, that there is no way to detect an Earth-sized planet with present technology. Meanwhile, their data does suggest a third planet in the system, a possible Saturn-sized object. Others could lurk there.

    Laurance Doyle, a researcher at the SETI Institute who was not involved in the discovery, told SPACE.com the new finding "is a strong encouragement" that our solar system "may not, after all, be totally unusual."

    The Jupiter-like planet has another potential benefit, Doyle points out: Its gravity would lure comets, shielding inner planets from life-threatening bombardment. Jupiter plays this protective role in our solar system.

    Pushing the limit

    Marcy, Butler and their colleagues also announced today the lightest extrasolar planet ever found, one 40 times as massive as Earth.

    This discovery pushes the lower limits of their wobble method, which spots movement in a star induced by the gravity of an orbiting planet. (No confirmed planet outside our solar system has ever actually been photographed.)

    This relatively small planet, whose possible presence was first reported in May by SPACE.com, was detected around a star called HD 49674. It is just 15 percent the mass of Jupiter. Theory holds that it would be gaseous, not rocky. Previously, the lightest known extrasolar planet was more than 50 times heavier than Earth.

    For comparison, Neptune is about 17 times as massive as Earth and Saturn is about 95 times as heavy.

    Marcy has said the wobble method will not be able to find planets weighing less than 10 Earth-masses.

    The SETI Institute's Doyle uses a different method for planet hunting, however. He looks for slight dips in a star's light that indicate the passage of a planet. The method has yet to discover a planet, but it has been used to detect the atmosphere of a known extrasolar planet.

    This so-called transit method could spot a planet twice as big as Earth, Doyle says, if the planet's path is properly aligned so that it passes in front of the star as seen from Earth.

    Such a planet would have roughly eight times the mass of our own. It would still be rocky and could, theoretically, harbor life.

    Doyle said the existence of two planets bracketing the habitable zone around 55 Cancri "indicates that planet production may have taken place within the habitable zone of that system."

    Next Page: A dream come true, plus what's next

    ~

    Dream come true

    The discovery of the Jovian twin caps 17 years of planet hunting by Marcy and Butler, who were not deterred by early skepticism in their technique.

    "Way back in 1985, Paul Butler and I began sketching the idea for a new instrument, attached to a telescope, that might someday detect planets around other stars," Marcy told SPACE.com. "Some very smart people told us that we wouldn't succeed, that we would never detect the wobble of a star caused by its attendant planets."

    They did, beginning in 1995 just months after a European team found the first planet around a star besides our Sun. Marcy and Butler confirmed that finding and went on to become the world's most prolific planet-hunting team.

    "We always dreamed that maybe, with a wisp of phenomenal luck and dogged perseverance, we might capture evidence of a Jupiter-like planet," Marcy said.

    Prior to today's announcement, all known extrasolar planets orbited more closely to their host stars, some as close as Mercury is to our Sun.

    Because the planet around 55 Cancri takes 13 years to make a complete orbit, it took equally long for enough data to accumulate to definitively identify the object. Its orbit is elongated instead of being nearly circular like Jupiter's. "We haven't yet found an exact solar system analog," Butler said. "But this shows we are getting close."

    Other recent discoveries have shown that circular orbits do exist around other stars.

    Butler said more Jupiter-like planets will likely flow from the data they are collecting on 1,200 Sun-like stars.

    What's next

    While Doyle or someone else might find a planet twice the size of Earth, the discovery of a true Earth-sized planet won't come for at least a few years, most researchers agree.

    But now there is a perfect place to look.

    The 55 Cancri system "will be the best candidate for direct pictures" by a next-generation space-based observatory, said Debra Fischer, a UC Berkeley astronomer who is part of the Marcy-Butler team.

    Two such missions are planned by NASA, first the Space Interferometry Mission and then the Terrestrial Planet Finder. The discovery of a solar system with elements similar to our own "adds urgency to missions capable of detecting Earth-sized planets," said Charles Beichman, NASA's Origins Program chief scientist at the Jet Propulsion Laboratory in Pasadena.

    No firm launch dates are set for either of these satellites, however. Both would follow the less ambitious Kepler mission, set to launch in 2007. Kepler will use the transit method to detect and generate a census of Earth-like planets around other stars, assuming such planets exist, but it won't photograph any.

    Details of the research

    The star 55 Cancri is in the constellation Cancer. It is roughly 41 light-years from Earth and about 4.7 billion years old, comparable to our Sun.

    The new discoveries were funded by NASA and the National Science Foundation. Observations of 55 Cancri were made at the Lick Observatory. The Anglo-Australian telescope was used to find two of the other planets announced today.

    Other scientists who collaborated in the new findings: Steve Vogt, UC Santa Cruz; Greg Henry, Tennessee State University; Dimitri Pourbaix, Universite' Libre de Bruxelles; Hugh Jones, Liverpool John Moores University in the United Kingdom; Chris Tinney, Anglo-Australian Telescope; Chris McCarthy, Carnegie Institution of Washington; Brad Carter, University of Southern Queensland, Australia; and Alan Penny of the Rutherford Appleton Laboratory in the United Kingdom.

    The wobble method, which is so far responsible for all extrasolar planet discoveries, is also known as the Doppler technique. The researchers employ special filters in a telescope to measure a change in the wavelength in light coming from a star. The change results from the star moving toward the telescope and compressing the waves, and then moving away from the telescope and lengthening the waves.

    The effect is similar to the change in sound of a siren from an ambulance rushing toward you and then heading away.
  • Closer to home (Score:2, Interesting)

    by .sig (180877)
    With the money and resources that would be required to move to a new planet in a distant solar system, wouldn't it be far easier and cheaper and quicker to set up a colony on a planet/moon in our own system? They would need some sort of enclosed structure to survive, but could possibly begin terraforming that new world. Given how long it would take to find and inhabit a new earth, we could probably create one here quicker.

    As an added bonus, we could send much more people to mars much faster, since in the time it would take to reach even the closest star, let alone one with habitable worlds, we could make many many round-trip voyages to an in-system world. This would certainly help overcrowding here on earth, and also get us started on interplanetary colonization. Once we actually got experience moving to new worlds, each successive one could only get easier, and with people on more than one world, there would most likely be more motivation for development of new technologies to make the trip faster and more efficent, as well as improving communication times.

    Maybe it's just me, but I'd rather be on a hostile new world now than a less hostile one in a few million years.
    • Re:Closer to home (Score:2, Insightful)

      by electrick (579755)

      There was an episode of a canadian radio show called Quirks and Quarks that talked about what would be needed to set up colonies on planets in other solar systems. They spoke of the fact that it wouldn't be the people that embarked on the voyage that would set up the new "earth" but rather, their children or grandchildren.

      This would present certin difficulties. For instance, how could one be sure that the children would be able to take over the duities of the parents, let alone want to? Can we be sure the children of extreamly brilliant people would be brilliant themselves? And how could we be sure they wouldn't just flip out and kill each other because of the very closed conditions of the craft?

      Perhaps the most interesting point made was the question, how will the children of the origional voyagers cope with life off of the ship? For generations these people would be used to life on the ship, there is doubt that they would be able to function in the "outside world".

      As much as I'd love to see humans on planets outside of this solar system, I agree with your veiws on setting up colonies in this system. It is viable in the short term, unlike further voyages that would require many more years of planning.

    • other plantes wouldn't have the slightest impact on overcrowding. Until we figured out how to move BILLIONS of people off the planet, cheaper than we could kill them.

      And even if we did trim the population from say, 10 billion, back down to 6 or so - wouldn't it be a very short while before we were back up to 10 again?

      Face it - the ONLY hope of easing overcrowding is population control. And there are only TWO ways to control population. A strong totalitarian government, or (apparently) global industrialization. Or, I suppose the old standby's, war, plague, famine.
  • The article doesn't give much information about this, so I figured I'd put in my 2 cents from what I learned in astronomy this year:

    Currently, they have 2 ways (that I'm familiar with) to find an extra-solar planet. First, they can look for a "wobble" in the path the star takes. This wobble is caused by the gravitational pull of a large planet orbiting the star. Earth is so small that the tiny wobble caused by a planet similar in size would be impossible to view; or at least it would disappear with the systematical error.

    The other way I've heard of to find extra-solar planets is similar to an eclipse. When the planet comes between the star and Earth, we can measure the changes in luminosity of the star. Obviously, with planets with small orbits, we can determine how quickly the planet orbits the star because of the pattern in the luminosity. Again, we can't detect earth size planets since earth is just too small.
  • The problem is that these are gas giants, like Jupiter or larger and we do not at this time have the tech to discover anything else.
  • by Rothfuss (47480) <chris@rothfuss.gmail@com> on Thursday June 13, 2002 @02:43PM (#3696255) Homepage
    Start building the fleet!

    I recommend employing shiny white robots as our attack force.

    -Rothfuss
    • by Dirtside (91468) on Thursday June 13, 2002 @04:15PM (#3696994) Journal
      No, no, we'll just use clones, they're more efficient -- and hey, I hear that the Kanadians just happen to have a fully-trained clone army ready to go. Man, those Kanadians are excellent cloners.

      What? I've only seen it three times, why?
  • Great! (Score:2, Funny)

    Soon, environmentalists won't be able to tell us not to pour motor oil down the sink because "It's the only planet we have".
  • which scientists are calling "third earth," is easily recognizable by a search-light cat head projected against its atmosphere from within. The new evidence irritates radio astronomers, who had initially written off the find as a hoax when the only signal they received was some guy yelling "Ho!"

  • You might want to look at Jean Schneider's Extrasolar Planetary Encylopedia [obspm.fr] for a lot more information, including accurate information that hasn't been put through the popular press. :D

    After all, we ALL know how precise the media is, right?

    55 Canri, btw, has been on the extrasolar planetary astronomy watch list for some time. Read the paper references at Jean's site. I wondered why it looked so familiar...
  • by Loundry (4143) on Thursday June 13, 2002 @03:16PM (#3696502) Journal
    This is not a troll -- I'm genuinely very curious.

    What do Christians think about stories like this? I ask becuase, in discussions with Christians, I've heard Christians tell me that there is no intelligent life on other planets. This was usually in response to my questions like, "Did Jesus die for aliens on other planets?" Perhaps a silly question for me to ask, but the "There is no intelligent life on other planets" was not an uncommon belief among the Christians I've met.

    So I've often wondered what Christians (particularly Christian nerds, who are probably significantly more friendly to science than some of the Christians I've met) think when stories like thit surface and hint at the possibility of finding other "Earth-like" planets that may have intelligent life on them.

    Thoughts?
    • Perhaps this link may be helpful to you:

      What does the Bible say about intelligent life on other planets? [christiananswers.net]
      • but then again, the scriptures say Pi=3, so what's the point? You either have to bend reality to accept that belief (that circles are hexagons), or you have to accept scriptural fallability. If you accept scriptural fallability, a whole lot of other things collapse with it. Unfortunately. Maintaining a belief in the Divine does not require belief in scriptural infallability - but it does make it awful hard to justify things like, church, and observance of religious laws, and the portrayed history of the OT-era.
      • i really wish people on slashdot would realize that fundamentalist!=Christian.
        fundamentalist is a subset of Christian. to pass that site off as indicative of all Christian belief is about as irresponsible as equating Islam with terrorism, and just as ignorant.
        i'm not very Christian myself anymore, but I still find such generalizations insulting.
    • hmmmm (Score:2, Insightful)

      by coronaride (222264)
      as a follower of Christ who specializes in nerdiness/geekiness, i feel obligated to answer your questions.

      while the bible does not specifically state that there is life on other planets, it never says that there isn't life on other planets. i, personally, believe that there isn't life, even though i know this is total flamebait. this is my belief and it is based on feelings, not facts. i would venture to believe that the feelings i have that lead me to believe this are probably similar to one's feelings that would lead one to believe that because there are other planets, there's a possibility that life exists on them. We currently have no evidence that really proves that extra-terrestrial life exists, but we have no evidence that really proves that extra-terrestrial life doesn't exist. Very similar to my faith, in that I have no rock-solid evidence that proves that my God exists but I have no rock-solid evidence against Him, either. That's why it's called faith..

      As far as Jesus dying for the sins of aliens on other planets..hmm..it really depends on a couple of things. First of all, if we are to believe that the fall of man was confined only to earth, then I would probably say that yes, Jesus did only die for the sins of those who live on earth..e.g. "For God so loved the WORLD" -- However, I believe that man's fall was universal, and therefore I would have to say that the universe, in turn, was entirely effected.

      Many questions remain, even though none have really been answered.. if aliens exist, why do we assume that it would be intelligent life and not like a martian dog or rat or something? if the life is intelligent, does it have a soul that is saveable, according to Christian theology? hmmm..much meditation and critical thinking is required here..

      What do you think about this?
    • Really, it depends on what kind of Christians you're talking to. I'm a Christian, and I believe there is most likely intelligent life somewhere else in the Universe. That is because I believe the Bible (New Testament, anyway) is a moral compass, not a historical record. I've seen cases made by "Every Word of the Bible is Absolute Truth" Christians, and I find them hollow...they make definitive assertions based on nuance of language. The Bible says "All of creation..." and they assume that means the entire Universe, not just Earth. I think of it more like this: Jesus taught in parables, why wouldn't God communicate in the same way to the authors of the bible? Do you really think the authors of Genesis would understand the formation of the solar system, the evolution of life on earth (guided by God), and time spans in the millions of years? Of course not! So He explained it in a way they could understand...through a parable about the creation of the Earth in the span of days.

      Some Christians, however, do not understand this concept. This is the scariest glimpse into these peoples' minds I have from personal experience. When I was in the 9th grade, about 10 years ago, several of my friends at school and I were arguing about creation and evolution. One of the girls was a southern Baptist, and said her church was having a lecture on the topic for their youth group the next week. So the six or so of us decided to go. The guy leading the discussion was, of course, pro-creation, and that's fine...it's what I expected to find at a Baptist church event. Now, during the course of the lecture he asked the audience, "How old is the Earth?" One young adult raised his hand and responded "ten thousand years." Another said 6k. I raised my hand and said, "Four and a half billion years old."

      They laughed at me. The entire audience turned around and laughed at me. I was speechless. I couldn't imagine that even being a topic of debate. The speaker went on to inform us that the Earth was, in fact, only six thousand years old, because the Old Testament listed the various ages of people who lived since Adam up until times of historical record, and with a little math... Draw your on conclusions, but that incident alone taught me I would have to approach my faith with a heavy dose of skepticism, so I wouldn't wind up spouting impossibilities simply because they're written in a book.
      • I'm sure christians will realize how old the earth is soon enough, just like they were forced to realize earth wasn't flat. :-) Seriously, if that's what christianity stand for - laughing at people with completely legitimate opinions, just being different from what a book says, then it's nothing *I* would like to stand for... :-P
        • I'm sure christians will realize how old the earth is soon enough, just like they were forced to realize earth wasn't flat. :-) Seriously, if that's what christianity stand for - laughing at people with completely legitimate opinions, just being different from what a book says, then it's nothing *I* would like to stand for... :-P

          What most people don't realize is being a Christian does not mean standing up for Christianity. It means standing up for Jesus Christ.

          I call myself a Christian.
          I believe there could be life on other planets.
          I don't agree with many Christian teachings, and recognize the fact that the Bible was written by man, may be flawed, and even if it isn't flawed it's still very difficult to comprehend. Ten people can read the same passage and get ten different answers from it. Who knows which one is right.

          Being a Christian means believing in Jesus and that he died for your sins. It also means living your life for him. That's mostly it. As a Christian, I try hard to live the way Jesus would want me to live. I do my best to treat everyone with kindness and respect.

          Those people that ridiculed the original poster were not living their lives for Christ. I wouldn't call them Christians, nor would I want anything to do with them, either. Don't confuse nasty "Christian" behavior with a hatred for Jesus. I assure you, he is also unhappy with their behavior.
        • I'm sure christians will realize how old the earth is soon enough, just like they were forced to realize earth wasn't flat. :-)

          Slight problem with that. We can sail in a boat and find that the world really isn't flat. We can make a logical argument that sky charts just work better if we call the sun the center of the solar system. But we can't hop in our time machine and go back 10,000 years to see if the Earth is there or not.

          After all, God could have just set it all up as a kind of history lesson, so we could figure out how creation was going to work from creation on.

    • As a fundamentalist Christian, and an ordained Southern Baptist minister with an MS in Software Engineering, I'd be happy to offer my thoughts on your question.

      First off, I would agree whole-heartedly with the previous poster who commented that much depends on whether the life discovered was (is) intelligent, and whether or not it has a soul.

      As far as what I think about stories like this... I don't find any conflicts between my faith and these kinds of articles. The Bible makes mention of creatures such as the Nephilim who lived or visited Earth prior to the flood. And any Christian who would take the time to thoroughly study the Bible would be compelled (I think) to conclude that there is much that we don't know or understand about our situation in the grand scheme of things. If you're going to accept that there are angels, seraphim, cherubim, demons, etc... then they, by definition are "extra-terrestial." I do believe in a Creator, and that Jesus Christ was the Creator incarnate. Simple logic would lead one to believe that if He created life here, he could, at His discretion, have created it elsewhere. (One reason I run seti@home, just out of curiosity)

      A thorough study of the Bible must entail at least a passing familiarity with the language(s) from which the version you're reading was translated. The gospel of John tells us that Jesus Christ died for the sins of the world. (...For God so loved the world...) The Greek word which was translated "world" is "kosmos: the world, the universe."

      Like others, I'm saddened to find Christians, or for that matter, anyone, who seems to cling to the belief that they have the final answer to any question. From the Pope on down, none of us can pretend to even begin to comprehend the magnificence of God. Therefore, when I see articles like the one we're discussing, it thrills me to see that we've uncovered one more small piece of the mystery of God's creation.

      One final note, I've had bad experiences with fundamentalists just like others have. Any group of people will have their lowest common denominators. Scientists can be just as dogmatic about their theories as many zealots are about their theology. Read / study the Bible for yourself, and draw your conclusions.

      Hope I haven't been too tangential.

    • What do Christians think about stories like this?


      Well, whatever they think... fact remains, there are planets orbiting other stars, and they've found at least one with an athmosphere. If they don't like it, they can do what they do with other science that goes against their belief system; close their eyes and hope it will go away.

      I ask becuase, in discussions with Christians, I've heard Christians tell me that there is no intelligent life on other planets.


      As far as I know, noone knows whether this is true or not. Saying that there is or is not alien life, and being very sure when there is no clear evidence in either direction, is not any different from being very sure when saying there is a god when there's absolutely no evidence.

      So I've often wondered what Christians (particularly Christian nerds, who are probably significantly more friendly to science than some of the Christians I've met) think when stories like thit surface and hint at the possibility of finding other "Earth-like" planets that may have intelligent life on them.


      Well, I for one am glad that this is not the mideavals or the dark ages, where the church had all the power and intended to keep it that way, by punishing, for example, scientists that dared to make discoveries and even publish them.


      So, what if the scientists discover life and even intelligent life on other planets? What will happen, especially if christians can't stand the truth? Will they try to stop schools from teaching these new findings, as they are trying with various success stop the teaching of evolution, and before that, tried to stop Galileo Galilei to publish his book where he describes how the earth is orbiting the sun and not vice versa?



      Science can never be blasphemous even if there IS a god. I am pretty sure that a god that created us would let us see the universe he created, for would that not be flattering him; trying so hard to see it all? Aren't christians (or other religious ones) always talking about the Truth? Then why not let us see the truth?


      If there is a god, he has never tried to stop us from seeing his creation - only human beings that are arrogant enough to claim to have some sort of directions from, and communication with god has ever tried to stop it. Never let them do that.

    • Revelations. Is it just me, or could this very well fit into an alien attack? Orbital bombardment, bio/chemical weapons, the whole nine yards.

      Anyway, I'm Christian, and it's a tough question to answer. I saw somebody had a link addressing the issue, but I can't say I was too impressed by it. I'm under the personal opinion the Bible is a biography on what we need to know, not what we want to know. It tells about the things revelant to us. Creation relative to us.

      "Did Jesus die for Aliens on other planets?" That really depend on how broadly you want to define a gentile. in the Bible, it pretty much refered to any man not a Jew. Again, the Bible was mainly skewed to Earth. I would think that if God did create other races, that something similar might have happened with them. After all, free choice seems to be a reoccuring theme with his creations (Men, Angels). Unless those other races were perfect, I'd think they may have (or will) be given the same opportunity. Somehow. Not meaning this in any demeaning fasion, but a Jesus on every alien world? Why not, he can obviously transend our physical limitations. Or maybe one every 5 races, the rest being a galactic form of Gentile. Beats the heck out of me. It makes for interesting musings, but not something I'll lose sleep over. My Jesus was more than enough for me.

      And here's an interesting bone to pick... If we are the only intelligent life in creation, is it really a terrible waste of space, considering the Lord saw fit to make us unique amoung entire Galaxies? I'd consider it an honor. Of course, I'm saved, so I consider it an honor ET's or no.

      Serious discussion is welcome as are trolls... After all, I need a good laugh every now and then.
    • First off, I'm just fine and dandy with there being intelligent life on other plannets. As to if they know about God or have been overrun by atheism, well, we'll figure that out when we get there, I guess.

      As for J.C. diying for the sins of aliens--that's a real loaded question. On the one hand, if the Word of God dies on every world, we diminish the guy we all know and love. On the other, if he *doesn't* die on every world for every alien's sins, then we get really egocentric.

      Then again, maybe aliens have evolved to the point where they can't sin... y'know, like giant beings of energy that can percieve God the way you or I would percieve a person right next to us.

      As to something to say to those Christians... ask them to point you to the biblical passages that tell where angels came from (AFAIK, there aren't any cannonical ones), and ask them about the biblical lack of North America, South America, Antartica, and Austrailia.

      Only mentioning three out of four continents is a pretty good indicator that lack of mention in the bible doesn't mean a thing doesn't exist.
  • by Peale (9155) on Thursday June 13, 2002 @03:18PM (#3696515) Homepage Journal
    It's only a matter of time until the Terrestrial Planet Finder program gets going and finds another Earth

    Yep. And when that happens, I'm leaving.
  • by CheshireCatCO (185193) on Thursday June 13, 2002 @03:28PM (#3696602) Homepage
    What bothers me about this is that while there is a quick mention of "formation models," most of the discussion of the potential existence of a terrestrial planet seemed focused on the stability of an orbit in the present configuration. In fact, it isn't clear to me that they've even considered the formation processes at all. (To be honest, I get the opposite sense.)

    Why does this bother me, you ask? Because an orbit at 1 AU might be stable NOW, but if you have a giant planet migrating in through the inner solar system to an 15-day orbit, it'll wreck jolly hell with any planets it passes. The migration is slow enough that you are almost guaranteed a close-enounter of some kind. Once a Earth-sized planet gets near a giant planet, the orbit is in the very least highly perturbed. Odds are fair that it could be ejected altogher or will collide with the giant planet and be effectly lost. But even if it isn't, the eccentricity is probably going to be increases substantially. A planet that changes its distance from its star radically over a year is unlikely to be habitable, if you believe current models.
  • Even though I'm still young, the one thing that I hope I live to see is the discovery of other life in the universe. If nothing else but to give a big Nelson "Ha ha." to all the people who believed otherwise. Billions and billions.
  • by ThesQuid (86789) <a987 AT mac DOT com> on Thursday June 13, 2002 @05:07PM (#3697357) Journal
    Quote from the Yahoo article about the same thing: [yahoo.com]

    55 Cancri is located 41 million light-years from the Earth, in the constellation of Cancer. The star, believed to be around five billion years old, is visible to the naked eye, astronomers said.

    HA! I don't think so. That's about 20 times the distance to the Andromeda Galaxy. Nice how the people they have writing these things up have a good grasp on the fundamentals of the subject matter.

  • When are we going to find the planet that is inhabited by beautiful women who love scientists, engineers, and computer geeks?
  • The Odds (Score:3, Interesting)

    by extrasolar (28341) on Thursday June 13, 2002 @07:02PM (#3698070) Homepage Journal
    By now, I am readily convinced that there is other life in the universe. In fact, it seems that odds are greater that there isn't life in the universe.

    But if I'm like most anyone else, the possibility of life on the western spiral of the Andromeda Galaxy just isn't useful. Its simply too far. We would never recieve a radio transmission from there and its too far to travel.

    First, lets assume Einstein is correct and we can not travel faster than the speed of light. In addition, lets rid our minds of all this science-fiction crap like wormholes and warp-drive. While I am naive, I'm not *that* naive.

    Lets take the nearest star. I've heard it is 4.3 light years away. That means a radio transmission originating their takes 4.3 years to travel here. Honestly, we could live with that. Of course that is not only assuming that that civilization has developed technology, but it also assumes that they haven't been exinct by some means.

    But, we're pretty sure there isn't a planetary system around proxima centauri. So we have to look farther out. But how long are we willing to wait for a round of communication from us to them? One hundred years? One thousand years? A hundred-thousand years?

    Okay, as a second consideration, how long does a civilization last once it discovers radio? We've only had radio technology for a relatively little time. How much longer will we continue to exist? Take HG Wells Time Machine. Will we unlearn our technology and instead progress towards a native happiness? What about other civilizations?

    In all, what are the odds that not only life exists in the universe, but that it is close enough and that it is in their technological prime?

    I'd fashion that the odds are astronomical against us.

The sooner all the animals are extinct, the sooner we'll find their money. - Ed Bluestone

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