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Space Science

New Transiting Extrasolar Planet 25

Shooter6947 writes "A new transiting extrasolar planet has been announced -- the only other known object that passes between its star and the Earth each orbit, a situation known as a transit, is HD209458b. The new planet, OGLE-TR-56b, is 0.9 times the mass of our own Jupiter and 1.3 times Jupiter's radius. It is the closest-in extrasolar planet yet found, with its year being only 1.2 days! Read about it from a cnn.com article or from the original scientific paper."
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New Transiting Extrasolar Planet

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  • by MacAndrew ( 463832 ) on Tuesday January 07, 2003 @06:56PM (#5036008) Homepage
    29-hour day? Must be very very close to its star. Ah, I see, 1/50 of Earth's orbit. Hmm, 3000 degree atmosphere.

    Hold off on the colony ships.

    However good the odds are that there are Earth-like planets in the galaxy, what are the odds that any are within reach of any human exploration that will ever take place? It's a big place, and barring "warp drive" the prospects of anything more than observation seem dim.

    Amazing what astronomers can do with impossibly minute signals over unimaginably great distances, esp. the inferences of size and density. I wonder what alien astonomers looking at our solar system are thinking? (Something like: "No chance intelligent life could exist there.")
    • by Captain Nitpick ( 16515 ) on Tuesday January 07, 2003 @07:49PM (#5036434)
      29-hour day? Must be very very close to its star.

      That's a 29-hour year. A 29-hour day isn't impressive in any way.

      Hold off on the colony ships.

      It's a gas giant. Colony ships wouldn't be useful even if it was at a livable temperature. Granted, overly large moons might be habitable for some gas giants, but we'd have to be able to find them first.

      I wonder what alien astonomers looking at our solar system are thinking? (Something like: "No chance intelligent life could exist there.")

      Molecular oxygen in an atmosphere implies life of some sort, as most non-biological processes reduce the amount of free oxygen. Once you've got evidence of life, you've crossed one of the major hurdles to finding intelligent life.

      If you've got enough viewing ability to take spectral readings of individual planets in a system, you can make pretty good guesses about which ones have some sort of life on them.

      If our alien astronomers have a technology level equivalent to ours roughly ten years ago or earlier, they're not going to see anything other than the Sun. If they're as advanced as we are, they might be able to see Jupiter, if they're close enough. If they're more advanced, then what they can tell about us depends on just how advanced they are.

      • It's a gas giant. Colony ships wouldn't be useful even if it was at a livable temperature. Granted, overly large moons might be habitable for some gas giants, but we'd have to be able to find them first.

        Wouldn't this be more likely to be a very large rocky object? That close to the star, I'd expect volatiles to be stripped.
        • Wouldn't this be more likely to be a very large rocky object? That close to the star, I'd expect volatiles to be stripped.

          The writeup says the planet has 0.9 times Jupiter's mass, and the article says it has a temperature of 3100 F. This probably means it is not a true gas giant (whoopsie), but it is still hot enough to melt silicon and iron, so there's still no solid surface. Imagine a planet of magma. Were it to cool off, it should become a very large rocky object.

          As it is, there's nothing to land on, and it's too hot for a ship to survive. And even if it were cool enough to safely land on, the gravity would be too high for human habitation.

          • The writeup says the planet has 0.9 times Jupiter's mass, and the article says it has a temperature of 3100 F. This probably means it is not a true gas giant (whoopsie), but it is still hot enough to melt silicon and iron, so there's still no solid surface. Imagine a planet of magma. Were it to cool off, it should become a very large rocky object.

            As it is, there's nothing to land on, and it's too hot for a ship to survive. And even if it were cool enough to safely land on, the gravity would be too high for human habitation.


            Hmm. That paints an interesting picture. A few relatively common substances (like aluminum oxide) should be solid at those temperatures. Depending on their buoyancy relative to other components (mostly silicates), you might end up with a solid crust (modulo enough convection churn to make the San Andreas fault look like a nice picnic spot). This of course assumes that enough oxygen was bound into oxides in the first place, instead of mostly being bound as water and being stripped early in the planet's life/blown away to the outer system during accretion.

            As for dropping probes into that ocean, an aluminum oxide shell should work quite well. Tungsten carbide-coated graphite might work too, being even more temperature-resistant, as long as it doesn't alloy with the surface material. It would be neat to try, though I doubt we'll get a chance any time soon :).

            How would you set up the electronics/instruments on the probe, though? Diamond semiconductors, carbon or tungsten wires, aluminum oxide optics? It's an interesting thought experiment.
    • I wonder what alien astonomers looking at our solar system are thinking? (Something like: "No chance intelligent life could exist there.")

      And they'd be right!
    • However good the odds are that there are Earth-like planets in the galaxy, what are the odds that any are within reach of any human exploration that will ever take place? It's a big place, and barring "warp drive" the prospects of anything more than observation seem dim.

      The odds kinds of depend on how long a trip we decide is worthwhile. In principle, we could build large, slow vessels that cross the distances between stars over generations. In the next twenty or thirty years, I would be surprised if some sort of 'hibernation' technique were not developed that could be applied to long trips. (I'm sure it would be designed for other, more profitable purposes, but would be useful nonetheless.) The real problem is that we have no good way (right now) of investigating potential destinations.

      Our current detection techniques are inadequate for observing (or inferring) an Earth-size planet at an Earth-normal distance from even the nearest stars. There could be Earth-like planets in our own stellar backyard, but we can't yet see them. All the current observations do is bolster the idea that the formation of planets is not in and of itself an unusual occurrance. To really do a proper planet search, we're going to need some long baseline interferometric telescopes--preferably including some in space so we can get good infrared data. With such telescopes, we can resolve (and do direct spectroscopic measurements on) Earth-size planets at light-year distances, looking for oxygen atmospheres and water vapour.

      Such observations (if they suggested any sort of life-bearing world) would no doubt spur quite a bit of research into techniques for interstellar travel. If I were a biologist, I'd gladly spend the rest of my life in space in exchange for a look at alien plankton--as long as I was reasonably sure there would be something to look at once I got there.

  • I like science. (Score:1, Offtopic)

    by Faldgan ( 13738 )
    Things like this make me feel good about the human race. Sure, we're rather argumentative, and spend most of our time fighting ourselves, but there is a chance that one day we won't. Right now we behave like a bored puppy that's been stuck inside the small kennel all of it's life. We might find something to do one of these days. We are finally figuring out how to look out the wire mesh that makes up our door, and noticing that there are other wire mesh cages out there. Whee!!! We (as a race) are growing. We're improving ourselves. We don't have very good control of our parts yet. (our "USA" part is about to launch an attack on our "Iran" part) but we *are* opening our eyes, and we *are* looking out there.
  • by GuyMannDude ( 574364 ) on Tuesday January 07, 2003 @08:03PM (#5036530) Journal

    The new planet, OGLE-TR-56b, is 0.9 times the mass of our own Jupiter and 1.3 times Jupiter's radius.

    My favorite heavenly body is the girl who lives across the street. I've named her OGLE-T&A-36DD. The best thing is that I don't even need a telescope to see her: binoculars work fine for seeing into her bedroom!

    GMD

  • if the planet temperature is 3100 degree F, then it must be made up of heavy metal. The only abundant heavy metal in the universe is iron, so it must be made up of iron. If the planet is of the size of jupiter, then the iron density in such a high gravity situation would be about 20 times of water, which gives it s mass of about 100 times Jupiter. This is just about a critical mass for star formation (to excite internal nuclear reaction). How did such a planet formed? If it was mostly H2, He cloud at birth, then it would have been a star! Also, where did all the iron came from (more iron than out entire solar system has)?

    I did some back of the envelope calculations, so I might be totally off track, but this seems really funny object.

    • Well, after reading the article, I did realize, I was totally offtrack. just ignore the original post.
    • by Anonymous Coward
      Look at the graphs of energy released vs proton number. It is very low, and incredibly steep at the start, peaks at iron, and goes down at the end(near uranium and other very heavy metals). This is why fusion (going from say 1 proton in hydrogen to 2 in helium) creates energy, as well as breaking something big like uranium in chunks also provides energy.

      What this means is that any materials south of iron can be fusioned to create energy(though maybe not enough to self-sustain), and any north of iron can be fissioned to create energy, but iron itself is "nuclearly inert" (for lack of a better catch phrase), so it's possible the 'iron planet' is debris of a star, but it could never reach critical mass 'cause it already has.
      • Actually, iron, and everything above it, is fusible. The issue is that it requires more energy to get them to fuse then is gained by the fusion process. In practice, only one physical process produces enough energy to fuse iron: supernovas. Under those conditions everything above iron is formed. Why do you think we have heavy elements?
      • Just curious, is it a coincidence that Iron just happens to be the most magnetically attractive element as well, or is there a relation?
        • by Anonymous Coward
          Touche wyldeling, iron can be transmuted, but it would happen only in a environment that already has protons flying around in it. (ie a star still burning hydrogen). A pure iron planet of any size would be in no danger of criticality.

          Actually iron is not the most magnetic, some rare earth magnets like molybdenum can be much stronger. I'd say its a coincidence, the atomic properties are to do mainly with the nucleus, whereas the chemical and magnetic properties are more to do with the outer shell of electrons.
  • According to the Harvard-Smithsonian [harvard.edu]
    Center for Astrophysics' article [harvard.edu], this is the farthest known planet @ ~1500 parsecs away (50 times farther than any discovered so far).
  • with its year being only 1.2 days!


    I don't know what you were reading, but the website you link to says:

    Orbital period: 3.524738 ± 0.000015 d.

    which looks like ~3.52 days in the year to me.

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