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Discovery of Oldest Known Asteroids

Calcium aluminum-rich inclusions (CAIs) are bright, ancient materials found in carbonaceous chondrite meteorites. Their story in terms of modern astronomy goes back to February 8, 1969, with the fall of the so-called Allende meteorite, the largest carbonaceous chondrite yet discovered. This meteorite, which fell over Chihuahua, Mexico, was found to be rich in CAIs, seen as inclusions of up to several centimeters in size. The link between CAIs and the early Solar System was soon established.

Allende meteorite

Carbonaceous chondrites are meteorites with high levels of water and organic compounds. the presence of which leads scientists to believe that they are relatively pristine examples of material from the birth of the Solar System. They are also known for the round grains known as chondrules. Now a team of astronomers has found asteroids likewise enriched in calcium and aluminum, and hence considered to be among the oldest yet identified. Says Tim McCoy (National Museum of Natural History):

“I find it amazing that it took us nearly 40 years to collect spectra of these [CAI-rich] objects and that those spectra would now initiate another revolution, pointing us to the asteroids that record this earliest stage in the history of our Solar System.”

Image: Allende, like many carbonaceous chondrites, contains calcium-aluminum-rich inclusions (CAIs). Unlike chondrules, which are round and composed mostly of silicate minerals like olivine and pyroxene, CAIs are predominantly white to light gray in color, irregularly shaped, and rich in refractory (high- temperature) minerals like melilite and spinel. They are believed to pre-date chondrules by at least 2 million years. Credit: D. Ball/Center for Meteorite Studies (ASU).

Calcium and aluminum would have been among the first materials to condense into solid particles as the gasses of the early solar nebula began to cool. Largely unchanged since they formed some 4.55 billion years ago, these asteroids actually predate the oldest meteorites found. Jessica Sunshine (University of Maryland), who led the scientific team, makes a strong case:

“Several CAI-rich asteroids have been identified that contain 2-3 times more CAI material than any known meteorite. Thus it appears ancient asteroids have indeed survived, and we know where they are.”

The team used the NASA Infrared Telescope Facility in Hawaii to run spectral analyses showing the distinctive signature of CAIs on asteroid surfaces. All of which is useful targeting information for future space missions, as a sample return from such an object would offer material laden with information about our system’s earliest era. The case for asteroid missions continues to be bolstered, both from the obvious scientific perspective on display here and from the point of view of planetary security. The two are hardly exclusive — what we learn from a visit to a near-Earth object will tune up our technology for main belt operations as well as helping us to assess impact threats.

The paper is Sunshine et al., “Ancient Asteroids Enriched in Refractory Inclusions,” published online by Science on March 20, 2008 (abstract).

Comments on this entry are closed.

  • James M. Essig April 2, 2008, 19:52

    Hi Paul;

    Thanks for posting this fine article on asteriods.

    It occurred to me that asteriods might in some cases have exotic elements and isotopes perhaps in minable qualities once the infrastructure was set up to effectively mine these asteriods.

    Perhaps exotic radionucleids could be mined wherein these isotopes could be used to power radio-isotopic generators, nuclear fission reactors, and systems for manned interstellar propulsion systems. Since there is a limited quantity of U-235 on Earth, save for breeding fission fuels in breeder reactors, the asteriods, at least in some instances might be a source of large supplies of fission fuels.

    I can imagine a thermonuclear fusion runway wherein thermo-nuclear devices would be distributed in a linear pattern ahead of a space craft and then detonated behind the space craft or within a cylindrical energy extraction chamber running along the length of the ships hull. Alternatively, the devices could be accellerated down huge rail guns with relativistic muzzle velocities wherein the velocity of the approaching nuclear devices from behind would closely and safely match that of the space craft as the space craft approached C.

    What if asteriods contain exotic superheavy elements that are proposed to exist within the so-called “Island of Stability” which have yet to be discovered. These isotopes may have novel and exotic nuclear properties perhaps allowing them to be used in the propulsion systems of interstellar manned space craft including but not limited to use as a reaction mass, use in propulsion system energization, and in nuclear device pulsed craft simmilar to those designed under Project Orion. Perhaps the massive study and utilization of exotic superheavies can lead to the discovery of other nuclear forces which might even be stronger than the strong nuclear force.

    Thanks;

    Jim

  • george scaglione April 3, 2008, 8:39

    jim yes sir,mining asteroids is without a doubt in the future hopefully the not too distant one at that.who was talking a couple of days ago about getting all the oil we will ever need from the vicinity of jupiter and saturn? also a good idea as i recall! thank you very much jim and everyone- your friend george

  • James M. Essig April 3, 2008, 19:30

    Hi George;

    Thanks for the enthusiastic response.

    I can imagine huge 10 million to 100 million metric tons freighters that ply the depths of the solar system extracting hydrogenous gases from various planetary locations and bringing them back to Earth. These and He-3 and/or He-4 could be used as nuclear fusion fuel for fusion rockets, fusion runway craft, thermonuclear device runway craft, beamed fusion fuel craft for practically forever.

    I once read a science fiction novel wherein an interstellar capable craft capable of doing superluminal velocities had a propulsion mechanism based on synthetically produced exotic chemical compounds with electromagnetic bonds that were so distended that the molecules extended into the future a short temporal distance from the present temporal location of the ship wherein this extension was utilized for operation of the ships propulsion system.

    Assuming that spatial, spatial-temporal, and/or temporal wormholes might exist as topological structures in the fabric of space time through general relativistic gravitational field effects, why not consider that the fundamental force of electromagnetism might similarly be used to produce analogous novel and exotic spatial, spatial-temporal, or temporal translational, transport, or extendedness effects. Space in not only fundamentally defined by general relativistic curvature based on gravity, but also has inherent electromagnetic properties such as its magnetic permeability and electric permittivity, and also, the existence of zero point virtual electromagnetic fluctuations that have been detected and measured in Casimar plate experimental apparatus. Some candidates for extremely distended electromagnetic bonds in compounds which might produce such exotic effects include the elements of Carbon, Hydogen, Nitrogen, Flourine, and Oxygen because of the extremely tight bonds that these elements form. I will have additional comments related to these concepts in the comming days on this thread.

    Thanks;

    Your Friend Jim

  • george scaglione April 4, 2008, 8:02

    jim,wow fantastic! those freighters probably sound like a real good idea and part of a drive that extends partly into the future!? wow!!!!!! when it comes to wormholes we will have to ask not only where are we but ,when (!) are we.thank you very much george

  • James M. Essig April 4, 2008, 11:37

    Hi George and other Folks;

    George, thanks for the insights on wormholes. I believe that super concentrated mass might be able to gravitationally produce some form of wormholes or a teleporting space time warp, even with mass concentrations that are not high enough to form an event horizon. My thinking is that if a super dense concentration of matter could be produced, (say one that produces a discontinuous or asymmetrical gravity field approaching the strength of but even significantly less than that near an event horizon of a black hole, but wherein the differential mass surface area element(s) or the differential area element(s) of an enclosing spherical region of space having a maximum gravitational flux density through them that is as much as 1/2 an order of magnitude or greater than those that have a minimum gravitational flux density through them), then a discontinuity in space time or a stress in space time as a result of the different levels of space time distortion caused by the variations of flux density just might open up a gravitational teleportation door in space and/or time, perhaps even a wormhole. No doubt, variations within the curl of the gravitational flux vector field of the asymmetrical mass and thus the asymmetrical resulting gravity field might also be helpful in setting up stress induced space time snapping or breakage or other distortions that could lead to teleporation and perhaps wormhole production.

    An analogous teleportation system might be doable using super intense electromagnetic fields emanating from extremely electrically charged mass lumps and/or extremely magnetized materials or other sources of extremely high magnetic fields. In fact, systems where the electrodynamic force flux density differs from among one or more surface area elements and/or spherical element(s) of an mass enclosing sphere with respect to other such surface area elements might induce an electromagnetic door in space time or an electromagnetic wormhole to enable teleportation into the past or future in space and perhaps over even cosmic distances. No doubt, setting up strong variations within the Curl of the electric and/or magnetic fields may perhaps facilitate the production of such EM based space time distortions.

    Thanks;

    Your Friend Jim

  • James M. Essig April 6, 2008, 19:22

    Hi George and other Folks;

    It occurred to me that using atomic nuclei with highly stressed nuclear bonds might produce a space time future and/or past extension of the present location of the effected nuclei in an analogous way that the super-distended bonds of the super stressed chemical bonds do according to the science fiction story from which I drew the concept as described in my posting above on April 3rd, 2008 at 19:30.

    By symmetry, other superstressed fields might result in the same type of phenomenon assumming the reference science fiction story has any hint of truth in it. Some such fields might be associated with supersymmetric mattergy and fields such as the sleptons, squarks, and the photino, the squarks and the gluinos, the gravitino, and the like.

    Note that the superheavy elements proposed to exist within the Island of Stability might have novel electromagnetic and strong nuclear force stressed properties that might somehow produce or be utilized or perhaps even be augmented to provide such space time present extension into the past or future. Perhaps asteriods have some stable super heavy isotopes or isotopes of known elements that could be put to good use.

    It is interesting to note the great deal of applications that have arisen from the discovery of radioactivity and then stable heavy fissionable elements, perhaps to be followed by the discovery of stable superheavy elements. I feel that if and when we discover stable super heavies, a lot of new physics will be uncovered.

    Thanks;

    Your Friend Jim

  • forrest noble April 24, 2008, 21:28

    Jim, George,

    OK I found you guys, Oldest Known Asteroids? I’m hoping that before I die they will find asteroids that pre-date the solar system. They should, it seems to me. They would have been the seed material that formed our solar system. Those asteroids that were larger than dust sized that did not heat up enough and were far enough away from the sun during the beginning solar ignition times where the entire solar system was very hot by conduction of materials within the beginning solar vortex– that would not have melted and reformed during this time. They still could have sharp edges like the asteroid above because of fragmentation by collisions.

    Mining the asteroid belt and building space colonies in the vicinity would conceivably be started within the next 100, I hope.

    your friend forrest

  • ljk January 12, 2009, 0:43

    Scientists Publish Evidence Of Asteroids With Earth-Like Crust

    College Park, MD (SPX) Jan 12, 2009 – Two rare meteorites found in Antarctica two years ago are from a previously unknown, ancient asteroid with an outer layer or crust similar in composition to the crust of Earth’s continents, reports a research team primarily composed of geochemists from the University of Maryland. Published in the January 8 issue of the journal Nature, this is the first ever finding of material from an asteroid … more

    http://www.spacedaily.com/reports/Scientists_Publish_Evidence_Of_Asteroids_With_Earth_Like_Crust_999.html