[meteorite-list] Three New 'Trojan' Asteroids Found Sharing Neptune's Orbit

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Fri Jun 16 04:07:10 2006
Message-ID: <006201c69118$a35cd310$3051e146_at_ATARIENGINE>

Hi, Everybody,


    I think you know I am not too easily boggled (as in
"That's mind-boggling!"), but one sentence in this press
release boggled me: "Evidence suggests that the Neptune
Trojans are more numerous than... the asteroids in the
main belt " MORE Neptune Trojans than Main Belt
Asteroids, Gracie? Did I hear that right?

    My first thought was, "Where you going to put them
all?" and then I realized that if instead of just being in or
along Neptune's orbit, they are scattered all over Neptune's
orbital sphere, why, they would cover the surface of a
sphere with a diameter of 7,500,000,000 miles, and a
sphere with a diameter of 7,500,000,000 miles covers
one heck of a lot of real estate! (Way too many zero's
for this email!) Lots and lots of room to fit those millions
of big rocks into!

    The second realization was that the statement, "The methods
used to observe the asteroids are not sensitive to objects so far
out of tilt with the rest of the solar system" is a complete mouthful
of weasel-words for "We never bothered to point the big tube
in that direction. Doh." If you never point the scope at where
they are, your method is solidly 100% non-sensitive to them!

    Seriously, all searches are restricted to a band within a certain
selected number of degrees of the ecliptic on the assumption
that there are no more highly inclined objects to look for, on
a statistical likelihood. Guess what?

    More Neptune Trojans than Main Belt Asteroids, huh?
Are any of'em as big as Ceres? At closest approach a bright
Ceres-sized asteroid at Neptune's distance would be 535
times dimmer than Ceres is, about magnitude 13, fading
to 15 or 16 at other parts of its orbit, and if it were a
reddened object like so many other outer system objects,
still fainter by another magnitude or so.

    It's well to recall the disputed 2003 EL61, discovered by
Brown with a Big Gun but not announced and by a Spanish
team with a smaller telescope and announced, and verified by
getting a shot of it through a lousy 12-inch scope. Bright as it
was, it should have been discovered long ago but had never
been noticed, because of the fact that it's OUT OF PLANE!
Nobody looked...

    A slew of big bumpers beyond Pluto, some with moons,
and a Planet bigger than Pluto... er, CUSE ME, an "object"
bigger than the Planet Pluto. Now an asteroid belt as big or
bigger than the Main Belt, of probable planetesimals for those
Plutonian Planets I posted so tediously about last year... It's clear:
THE OUTER SYSTEM IS WHERE'S IT'S HAPPENING!

    Been thinking about Migrating to Mars?
    Been saying that someday you're going to get in on the
Mining Boom in the Main Belt?
    Forever threatening to Jump Off for Jupiter?
    Yearning to buy that ticket for the Shuttle to Saturn?

    Forget it! It's a Waste of Time!

    The Outer Outer System is Where It's Happening!

    For further information,
 contact OOSCC (the Outer Outer
System Chamber of Commerce) at
http://sww.ooscc.nep.triton.com/ or
http://sww.ooscc.pl.charon.com/
or visit one of our many entertaining Expo's
on a World or Satellite near you.


Sterling K. Webb
--------------------------------------------------------
----- Original Message -----
From: "Ron Baalke" <baalke_at_zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
Sent: Thursday, June 15, 2006 8:20 PM
Subject: [meteorite-list] Three New 'Trojan' Asteroids Found
SharingNeptune's Orbit


>
> http://www.carnegieinstitution.org/neptune_trojans/default.html
>
> Carnegie Institution of Washington News Release
> Thursday, June 15, 2006
>
> Carnegie Contact: Dr. Scott Sheppard; sheppard_at_dtm.ciw.edu
> or (202) 270-0243
> Gemini Observatory Contact: Dr. Chadwick Trujillo; trujillo_at_gemini.edu
>
> For a copy of the paper contact Science at scipak_at_aaas.org, or
> (202) 326-6440
>
> Three new "Trojan" asteroids found sharing Neptune's orbit
>
> Washington, DC - Three new objects locked into roughly the same orbit as
> Neptune - called "Trojan" asteroids - have been found by researchers from
> the Carnegie Institution's Department of Terrestrial Magnetism (DTM) and
> the Gemini Observatory. The discovery offers evidence that Neptune, much
> like its big cousin Jupiter, hosts thick clouds of Trojans in its orbit,
> and that these asteroids probably share a common source. It also brings
> the total of known Neptune Trojans to four.
>
> "It is exciting to have quadrupled the known population of Neptune
> Trojans," said Carnegie Hubble Fellow Scott Sheppard, lead author of the
> study, which appears in the June 15 online issue of Science Express. "In
> the process, we have learned a lot both about how these asteroids become
> locked into their stable orbits, as well as what they might be made of,
> which makes the discovery especially rewarding."
>
> The recently discovered Neptune Trojans are only the fourth stable group
> of asteroids observed around the Sun. The others are the Kuiper Belt
> just beyond Neptune, the Jupiter Trojans, and the main asteroid belt
> between Mars and Jupiter. Evidence suggests that the Neptune Trojans are
> more numerous than either the asteroids in the main belt or the Jupiter
> Trojans, but they are hard to observe because they are so far away from
> the Sun. Astronomers therefore require the largest telescopes in the
> world equipped with sensitive digital cameras to detect them.
>
> Trojan asteroids cluster around one of two points that lead or trail the
> planet by about 60 degrees in its orbit, known as Lagrangian points. In
> these areas, the gravitational pull of the planet and the Sun combine to
> lock the asteroids into stable orbits synchronized with the planet.
> German Astronomer Max Wolf identified the first Jupiter Trojan in 1906,
> and since then, more than 1800 such asteroids have been identified
> marching along that planet's orbit. Because Trojan asteroids share a
> planet's orbit, they can help astronomers understand how planets form,
> and how the solar system evolved.
>
> Researchers theorized that Trojans might also flank other planets, but
> evidence for this has surfaced only recently. In 2001, the first Neptune
> Trojan was spotted in the planet's leading Lagrangian point. In 2004,
> Sheppard and Chadwick Trujillo of the Gemini Observatory, who is also an
> author on the current study, found the second Neptune Trojan using
> Carnegie's Magellan-Baade 6.5 meter telescope in Las Campanas, Chile.
> They found two more in 2005, bringing the total to four, and observed
> them again using the 8-meter Gemini North telescope on Mauna Kea in
> Hawaii in order to accurately determine their orbits. All four of the
> known Neptune Trojans reside in the planet's leading Lagrangian point.
>
> One of the new Trojans has an orbit that is more steeply tilted to the
> plane of the solar system than the other three. Although only this one
> has such a steep orbit, the methods used to observe the asteroids are
> not sensitive to objects so far out of tilt with the rest of the solar
> system. The very existence of this Trojan suggests that there are many
> more like it, and that Neptune's Trojans as a whole occupy thick clouds
> with complex, interlaced orbits.
>
> "We were really surprised to find a Neptune Trojan with such a large
> orbital inclination," Trujillo said. "The discovery of the one tilted
> Neptune Trojan implies that there may be many more far from the solar
> system plane than near the plane, and that the Trojans are really a
> 'cloud' or 'swarm' of objects co-orbiting with Neptune."
>
> A large population of high-inclination Neptune Trojans would rule out
> the possibility that they are left over from early in the solar system's
> history, since unaltered primordial asteroid groups should be closely
> aligned with the plane of the solar system. These clouds probably formed
> much like Jupiter's Trojan clouds did: once the giant planets settled
> into their paths around the Sun, any asteroid that happened to be in the
> Trojan region "froze" into its orbit.
>
> Sheppard and Trujillo also compared, for the first time, the colors of
> all four known Neptune Trojans. They are all about the same shade of
> pale red, suggesting that they share a similar origin and history.
> Although it is hard to tell for sure with only four on the books, the
> researchers believe that the Neptune Trojans might share a common origin
> with the Jupiter Trojans and outer irregular satellites of the giant
> planets. These objects might be the last remnants of the countless small
> bodies that formed in the giant planet region, most of which eventually
> became part of the planets or were tossed out of the solar system.
>
> ------------------------------------------------------------------------
>
> This paper includes data gathered with the Carnegie 6.5 meter Magellan
> Telescopes located at Las Campanas Observatory, Chile, and is based in
> part on observations obtained at the 8-meter Gemini North telescope on
> Mauna Kea in Hawaii. Funding for the work was provided by NASA and the
> Gemini partnership, which includes: the National Science Foundation
> (United States), the Particle Physics and Astronomy Research Council
> (United Kingdom), the National Research Council (Canada), CONICYT
> (Chile), the Australian Research Council (Australia), CNPq (Brazil) and
> CONICET (Argentina).
>
> The Carnegie Institution of Washington (www.carnegieinstitution.org>
> has been a pioneering force in basic scientific research since 1902.
> It is a private, nonprofit organization with six research departments
> throughout the U.S. Carnegie scientists are leaders in plant biology,
> developmental biology, astronomy, materials science, global ecology,
> and Earth and planetary science.
>
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Received on Fri 16 Jun 2006 03:44:02 AM PDT