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Space Science

In Search Of the Vulcans 28

Posted by timothy from the appropriate-technology dept.
jonerik writes: "No, not those Vulcans. The BBC has this article on the Southwest Research Institute's (SwRI) search for the Vulcanoids, a belt of perhaps a few hundred small asteroids (perhaps between one and 25 kilometers in diameter) theorized to exist inside of Mercury's orbit around the sun. Because of their closeness to the sun and small size, the asteroids - if they exist - would be hard to observe from the ground. To that end, a NASA F/A-18 is being used to conduct a search 'of the twilight sky near the Sun that is far darker and clearer than can be obtained from the ground,' says Dr. Dan Durda of SwRI. According to the article, 'The camera used in the latest search...is trained on the region of space close to the Sun after the star has dipped below the Earth's horizon. The camera grabs twilight images at a rate of 60 frames a second.' The researchers hope to have a better idea of whether or not the Vulcanoids exist in another month or two."
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In Search Of the Vulcans More

In Search Of the Vulcans

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  • sounds like a good excuse to re-test what they can do. or use it as a test bed for some anti-missle stuff.

    "no really, we are taking pictures of rocks in space..."
    • NASA has always used US military aircraft, from fighter planes to the SR-71. It's easier to borrow something that'll get you up to 40,000 - 70,000 feet and then return it then sit down and design a one-off design

      The Dryden flight centre has been using F-18's since 1987, first as a high angle of attack research aircraft, then as a chase plane, then the F-18SRA (System Research Aircraft - don't go calling em F/A-18's)

      Remember, they have an existing maintainance infrastructure, easily available spare parts and a very well-known aerodynamic model to start with, so why not mess with em a bit in the name of research ?
    • sounds like a good excuse to re-test what they can do.

      Huh? If the Navy wanted to perform tests of the F-18, they wouldn't need to make up some cockamamie cover story - they'd just fire one up over at Miramar and test the damned thing.

  • Why do this now? (Score:1, Insightful)

    by Twintop ( 579924 )
    I'm all for space exploration to discover and learn just about anything and everything we can about our solar system, galaxy, and universe. BUT, there has to be a priority list in my mind, and for me this doesn't seem as important as some other things, such as trying to send more craft (or even people) back to the moon or to Mars. Not to go off on a tangent or anything, but it's been nearly 30 years since man was last on the Moon. This was because NASA wanted to make a reusable spacecraft, and they have: the spaceshuttle. Isn't about time to work on something that can launch from the space shuttle and goto the moon, or are they waiting for the ISS to be completed first, which ironically would tack the numbe rof years since we were last on the moon upto about 40-50ish. Anyway, back to the topic at hand. To me atleast these asteroids circling around Mercury are like a bunch of little moons, agreed? If they were to say it'd take 6 months to a year or more, I'd be totally against it because of the cost. But a month or two for what information might come from these observations could be worth it. Who knows, have we ever really looked right next to the sun for an extended period of time?
    • I think they mean asteroids around the sun, within Mercury's orbit.

      • Ahh, now that I reread that set of sentances, I see what you mean. Even so, the same reasons I'm against this still remain.

        • Re:Why do this now? (Score:5, Insightful)

          by EvilBastard ( 77954 ) on Monday June 24, 2002 @09:37PM (#3760390) Homepage
          Why do this now ?

          Because they are there.

          * Maybe they'll be stable enough to mount a nice in close power station without having to worry about Mercury's gravity well

          * Maybe observing their orbits could point to some more information on the GU theory

          * Maybe they could lead to some more theory on planetary formation with formation of planets close to stellar bodies

          * Maybe the knowledge gained from this can lead to new designs on high-altitude fast turnaround observation of objects coming at us from the sun (Like, the last two near-miss asteroids)

          * Maybe they are completly unremarkable chunks of stone, worth two or three papers and then forgotten about.

          It's a ground based observation at objects too close to the sun for most observations, done on the cheap with minimal new hardware designs. I'd be very suprised if the total budget for this was much over 3 or 4 million total

          The things you want NASA to do ? Guess what - they are already doing them. It's just they like doing a wide variety of different things, because you never know when you'll find something interesting in an unexplored area of science.
    • Going to the Moon would cost billions of dollars. This project probably costs in the thousands. Arguing that we shouldn't be spending this money because we should be going to the Moon makes little sense, when you look at the numbers.
  • I thought longer exposure times, sky conditions and a stable camera were key in astrophotography.
    If I'm wrong please correct me, but mounting a camera on an f-18 dosen't sound like good practice.

    • Re:Hey (Score:3, Informative)

      by dpp ( 585742 )
      I thought longer exposure times, sky conditions and a stable camera were key in astrophotography. If I'm wrong please correct me, but mounting a camera on an f-18 dosen't sound like good practice.

      According to the SWUIS page [swri.edu] the 60 fps rate of the camera is used for jitter compensation, so presumably the fast frame rate is quicker than the characteristic timescale of the aircraft motions.

      An aside: for the larger aircraft-borne telescopes like the Stratospheric Observatory for Infrared Astronomy (SOFIA [nasa.gov]) the telescope is "as stable as a mountaintop telescope sitting on a 10 meter cement foundation" according to the FAQs [nasa.gov]. From that page:

      So how do you do this? First, you isolate the telescope from the airplane by mounting it on a spherical pressurized oil bearing. The plane shakes and quakes, but the telescope doesn't feel it. Second, you direct the wind away from the telescope by shaping the side of the airplane so as to deflect it, and install a little deflector fence on the edge of the telescope cavity as well. Third, you stabilize the telescope against sudden motion (wind does get through) by spinning three orthogonal gyroscopes which are rigidly attached to the structure, and fourth, you steer the telescope so as to keep it steady, by tracking a distant star and giving the telescope magnetical nudges to point it toward a fixed direction.

    • Why mount of an f-18, was Re:Hey (Score:4, Insightful)

      by chongo ( 113839 ) on Monday June 24, 2002 @09:25PM (#3760354) Homepage Journal
      The f-18 is able to chase/extend the time it spends in twilight. At middle North America latitudes (say 40 Deg. North) the twilight shadow moves over the ground at about 1275 km/hr (~793 MPH), well within reach of an f-18. A scope on the f-18 can stay within the twilight shadow for an extensive period of time.

      As for the concern about stable cameras, NASA has been flying mounted scopes for some time. The guidance and anti-vibration systems are good enough to conduct real astronomy. In fact, craft such as SOFIA [nasa.gov] are pushing the technology even further. Yes, scopes on aircraft is outstanding practice.

      One might, however, ask if the glare of the twilight combined with observing low to the horizon will impact their ability to find Vulcans. Compared to the Eclipse method, the f-18 observing conditions are poor (low in the horizon, reduced image brightness, glare from the Sun that just set, dust, etc.). On the other hand the number of minutes to observe during totality (see my other posting on this topic) are limited. A single f-18 run can rack up more minutes than ground based eclipse imagery can in a decade.

      Better would be to fly cameras on an f-18 or Concord or SR71 in the Moon's shadow during a total eclipse. You can get the best of both worlds.

      Better still would be to observe from space with a special telescope that can take images near the sun.

      NOTE: Scopes like the Hubble cannot look too close to the Sun for obvious reasons. That is why you have and will never see a Hubble image of Mercury, let alone Vulcan asteroids.

      Craft such as SOHO were not designed to look for Vulcans because they, if they exist, are too dim.

      Vulcan asteroids, if they exist, are very dim. Bright Vulcans would have been spotted long ago during some eclipse or if nothing else during the extensive Vulcan search in the late 1800's.

      Each method as its +/-'s as well as cost tradeoff. I wish this new Vulcan program all the best in the hopes that they can do what others have failed to do so far.

      • Better would be to fly cameras on an f-18 or Concord or SR71 in the Moon's shadow during a total eclipse. You can get the best of both worlds.

        The Blackbird and F-18 are pretty small, it'd be cramped in there... but Concorde's huge for a supersonic plane. You could get all sorts of kit aboard a suitably modified one of those.

        Trouble is, the expense. There are only a dozen or so of them in the world and there's no prospect of any more being built. NASA could buy one and refit it, but that would come to, ooh, at least a quarter of the cost of a Shuttle launch.

        The other thing is, if you're going to chase eclipses, how are you going to run the operation? There's a total eclipse every few years, that's fine, but they're rarely ideally placed. 1999 was great; a Concorde was indeed chartered and pursued the eclipse halfway across the Atlantic. The eclipse in December is from South Africa to Australia; also could be good. But too often you'll either strike the upper limit of Concorde's range, or have an eclipse which is largely overland. Most countries will take a dim view of a plane that size making the sonic boom over populated areas... there's a reason you can't get a Concorde from New York to Los Angeles, and it's not entirely that Boeing doesn't want BAe muscling in to the American market...
    • For an excellent article on camera stabilization with high-resolution cameras on helicopters, see This Article [nytimes.com] at the New York Times online (login required).

      Fighter jets are far more stable than helicopters.

  • looking for Vulcans during solar Eclipses (Score:4, Interesting)

    by chongo ( 113839 ) on Monday June 24, 2002 @08:12PM (#3760073) Homepage Journal
    For the past several years, astronomers have been looking for Vulcans during total solar eclipses. The hope is to catch a Vulcan asteroid on either side of the Sun during totality.

    Photos are taken during totality. One camera is stationed near the beginning of the totality path. A few more are placed in various places along the path. A final camera is placed near the end of the totality path. Typically there is about 2 to 3 hours time between the 1st and last camera images.

    The images are searched for faint moving objects that are in orbit around and near the sun.

    Thus far, a few comets have been detected but no Vulcan asteroids have been found.

  • The SEDS Nine Planets [seds.org] website has a nice review [seds.org] of the search for an intra-Mercurial planet (to be called, surprise surprise, Vulcan), back before Einstein explained away the discrepancies between Mercury's predicted and actual orbits.

    -dexter "still looking for planet x" riley

  • Too much sun? (Score:1, Troll)

    by Tablizer ( 95088 )
    Wouldn't the radiation pressure from the sun at that distance de-stablizes the orbits?

    It is theorized that sunlight even interferes with asteroids just beyond Mars if they have certain spins or colors. (Remember that /. story about painting asteroids to keep them from hitting Earth?) If the sun can mess up orbits out there, then near Mercury it must be something like 1000 times as strong.
    • Not really. Radiation pressure from the Sun only affects dust-sized particles.

      Unless you're thinking of the Yarkosky effect, in which the asteroid's spin and re-radiation can cause a drag? It's not clear that the Yarkosky effect is significant, actually. It's a subject of considerable investiagation right right now.

      Even if it is, the effect is has will drop like the radius of the body to the minus one power (you radiate proportional to your area, but mass - and thus acceleration - goes like radius cubed). It's usually thought of as potentially important for meteroids, but asteroids probably don't notice much.
  • If they ran this experiment from the south poles they would have a sunset/rise that can last for several days during the equinox, very clear sky and a bunch of other advantages. Have they considered it and dismissed it for some reasons ?

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