{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T17:21:17Z","timestamp":1791393677651,"version":"4.3.3"},"reference-count":46,"publisher":"American Association for the Advancement of Science (AAAS)","issue":"5875","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Science"],"published-print":{"date-parts":[[2008,4,25]]},"abstract":"<jats:p>\n            Calcium- and aluminum-rich inclusions (CAIs) occur in all classes of chondritic meteorites and contain refractory minerals predicted to be the first condensates from the solar nebula. Near-infrared spectra of CAIs have strong 2-micrometer absorptions, attributed to iron oxide\u2013bearing aluminous spinel. Similar absorptions are present in the telescopic spectra of several asteroids; modeling indicates that these contain \u223c30 \u00b1 10% CAIs (two to three times that of any meteorite). Survival of these undifferentiated, large (50- to 100-kilometer diameter) CAI-rich bodies suggests that they may have formed before the injection of radiogenic\n            <jats:sup>26<\/jats:sup>\n            Al into the solar system. They have also experienced only modest post-accretionary alteration. Thus, these asteroids have higher concentrations of CAI material, appear less altered, and are more ancient than any known sample in our meteorite collection, making them prime candidates for sample return.\n          <\/jats:p>","DOI":"10.1126\/science.1154340","type":"journal-article","created":{"date-parts":[[2008,3,21]],"date-time":"2008-03-21T01:43:32Z","timestamp":1206063812000},"page":"514-517","source":"Crossref","is-referenced-by-count":86,"title":["Ancient Asteroids Enriched in Refractory Inclusions"],"prefix":"10.1126","volume":"320","author":[{"given":"J. M.","family":"Sunshine","sequence":"first","affiliation":[{"name":"Department of Astronomy, University of Maryland, College Park, MD 20742, USA."},{"name":"Department of Physical Sciences, Kingsborough Community College of the City University of New York, Brooklyn, NY 11235, USA."},{"name":"Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA."},{"name":"Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 11024, USA."},{"name":"Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"suffix":"Jr.","given":"H. C.","family":"Connolly","sequence":"additional","affiliation":[{"name":"Department of Astronomy, University of Maryland, College Park, MD 20742, USA."},{"name":"Department of Physical Sciences, Kingsborough Community College of the City University of New York, Brooklyn, NY 11235, USA."},{"name":"Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA."},{"name":"Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 11024, USA."},{"name":"Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T. J.","family":"McCoy","sequence":"additional","affiliation":[{"name":"Department of Astronomy, University of Maryland, College Park, MD 20742, USA."},{"name":"Department of Physical Sciences, Kingsborough Community College of the City University of New York, Brooklyn, NY 11235, USA."},{"name":"Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA."},{"name":"Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 11024, USA."},{"name":"Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. J.","family":"Bus","sequence":"additional","affiliation":[{"name":"Department of Astronomy, University of Maryland, College Park, MD 20742, USA."},{"name":"Department of Physical Sciences, Kingsborough Community College of the City University of New York, Brooklyn, NY 11235, USA."},{"name":"Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA."},{"name":"Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 11024, USA."},{"name":"Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L. M.","family":"La Croix","sequence":"additional","affiliation":[{"name":"Department of Astronomy, University of Maryland, College Park, MD 20742, USA."},{"name":"Department of Physical Sciences, Kingsborough Community College of the City University of New York, Brooklyn, NY 11235, USA."},{"name":"Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA."},{"name":"Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 11024, USA."},{"name":"Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"221","reference":[{"key":"e_1_3_1_2_2","unstructured":"CAIs have been dated using lead isotopes at 4.566 billion years ago (+2 million years ago\/\u20131 million years ago) by All\u00e8gre et al . ( 36 ) and 4.5647 (\u00b10.0006) billion years ago by Amelin et al . ( 37 )."},{"key":"e_1_3_1_3_2","first-page":"3","year":"1998","unstructured":"A. J. Brearley, R. H. Jones, in Reviews In Mineralogy, Vol. 36, Planetary Materials, J. J. Papike, Ed. (Mineralogic Society of America, Washington, DC, 1998), pp. 3-1\u20133-398.","journal-title":"Reviews In Mineralogy, Vol. 36, Planetary Materials"},{"key":"e_1_3_1_4_2","first-page":"424","volume":"27","year":"1992","unstructured":"T. H. Burbine, M. J. Gaffey, J. F. Bell, Meteorit. Planet. Sci.27, 424 (1992).","journal-title":"Meteorit. Planet. Sci."},{"key":"e_1_3_1_5_2","unstructured":"Other common Fe-bearing silicates that have strong absorptions in the near infrared ( 38 ). Although pyroxene spectra have absorptions in the 2-\u03bcm region they have even stronger features near 1 \u03bcm. Conversely olivine spectra lack 2-\u03bcm absorptions and are instead characterized by a complex feature at 1 \u03bcm. It is on this basis (a strong 2-\u03bcm absorption in the absence of a stronger 1-\u03bcm feature) that spinel is spectrally identified."},{"key":"e_1_3_1_6_2","unstructured":"This nomenclature was primarily designed for use in classifying CAIs from CV3 meteorites. Over the last three decades other descriptive terminology has been developed for other chondrite types ( 9 39 )."},{"key":"e_1_3_1_7_2","first-page":"383","year":"2006","unstructured":"H. C. Connolly Jr., S. J. Desch, R. D. Ash, R. H. Jones, in Meteorites and the Early Solar System II, D. S. Lauretta, H. Y. McSween Jr., Eds. (Univ. of Arizona Press, Tucson, AZ, 2006), pp. 383\u2013397.","journal-title":"Meteorites and the Early Solar System II"},{"key":"e_1_3_1_8_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1135842"},{"key":"e_1_3_1_9_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1147273"},{"key":"e_1_3_1_10_2","first-page":"746","year":"1988","unstructured":"G. J. MacPherson, D. A. Wark, J. T. Armstrong, in Meteorites and the Early Solar System, J. F. Kerridge, M. S. Matthews, Eds. (Univ. of Arizona Press, Tucson, AZ, 1988), pp. 746\u2013807.","journal-title":"Meteorites and the Early Solar System"},{"key":"e_1_3_1_11_2","unstructured":"The Smithsonian Allende sample USNM 3509 was sectioned into large slices and refractory inclusions were identified and cored. Thin and thick sections were made from half of the objects and reference materials were preserved for future study. Thin sections were analyzed by the Cameca SX50 electron microprobe at the Lunar and Planetary Laboratory at the University of Arizona to quantify major and minor element abundances. While avoiding contamination from the matrix material from the other half of the objects was cored out ground into <38-\u03bcm-size powders and sent to Brown University for spectral measurements at the NASA-Keck Reflectance Experiment Laboratory (RELAB) facility ( 40 ). All spectra were measured with 5-nm resolution at a standard viewing geometry of 30\u00b0 incidence 0\u00b0 emission."},{"key":"e_1_3_1_12_2","doi-asserted-by":"publisher","DOI":"10.1006\/icar.1995.1075"},{"key":"e_1_3_1_13_2","doi-asserted-by":"publisher","DOI":"10.1006\/icar.2002.6857"},{"key":"e_1_3_1_14_2","doi-asserted-by":"publisher","DOI":"10.1117\/12.551107"},{"key":"e_1_3_1_15_2","unstructured":"In the Bus visible asteroid taxonomy objects with a steep red spectral slope at wavelengths up to 0.75 \u03bcm which are then relatively flat are classified as L types ( 41 )."},{"key":"e_1_3_1_16_2","unstructured":"S. J. Bus thesis Massachusetts Institute of Technology (1999)."},{"key":"e_1_3_1_17_2","doi-asserted-by":"publisher","DOI":"10.1006\/icar.1995.1127"},{"key":"e_1_3_1_18_2","unstructured":"Whereas the Henan and Watsonia families are roughly the same distance from the sun the mean orbits of asteroids making up these two families are markedly different in both eccentricity and inclination. The mean proper elements for the Henan family are \u223c2.73 astronomical units (AU) (ranging from 2.69 to 2.76 AU) e \u223c 0.07 and sin( i ) \u223c 0.06 (where e is eccentricity and i is inclination) compared with the Watsonia family at \u223c2.77 AU (ranging from 2.74 to 2.80 AU) e \u223c 0.16 and sin( i ) \u223c0.29. This corresponds to a difference in orbital velocity between these families of over 6 km\/s making it highly unlikely these two families can be linked to a single parent body. 234 Barbara is a distinct asteroid located at 2.39 AU."},{"key":"e_1_3_1_19_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1945-5100.2004.tb00918.x"},{"key":"e_1_3_1_20_2","first-page":"1640","year":"1999","unstructured":"J. M. Sunshine, E. A. Cloutis, Lunar Planet. Sci.XXXI, 1640 (1999).","journal-title":"Lunar Planet. Sci."},{"key":"e_1_3_1_21_2","doi-asserted-by":"publisher","DOI":"10.1006\/icar.1993.1150"},{"key":"e_1_3_1_22_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1945-5100.1990.tb00717.x"},{"key":"e_1_3_1_23_2","doi-asserted-by":"crossref","unstructured":"B. Hapke Theory of Reflectance and Emittance Spectroscopy (Cambridge Univ. Press New York 1993).","DOI":"10.1017\/CBO9780511524998"},{"key":"e_1_3_1_24_2","unstructured":"To calculate the single-scattering albedo of each component we employed Hapke's two-stream approximation assuming no opposition effect isotropic scattering and that all components have the same density and particle size ( 22 ). Once converted to single-scattering albedo mixing is linear and relative abundances can be estimated using a least-squares solution ( 42 43 )."},{"key":"e_1_3_1_25_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.265.5178.1543"},{"key":"e_1_3_1_26_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.289.5487.2088"},{"key":"e_1_3_1_27_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1126164"},{"key":"e_1_3_1_28_2","unstructured":"Asteroid spectra are routinely measured relative to a given wavelength as in Fig. 3 where data are normalized to 0.55 \u03bcm. Absolute albedos are obtained from the Infrared Astronomical Satellite (IRAS) Supplemental IRAS Minor Planet Survey database as archived in the NASA Planetary Data System data set IRAS-A-FPA-3-RDR-IMPS-V6.0."},{"key":"e_1_3_1_29_2","unstructured":"Overall the asteroid spectra are red-sloped; i.e. they increase in reflectance with increasing wavelength. This is typical of asteroid spectra and generally thought to be related to either the presence of opaque phases or weathering in the space environment ( 44 45 )."},{"key":"e_1_3_1_30_2","unstructured":"Although the spectrum of 2448 Sholokhov is not uniquely interpretable its presence within the same family as several spinel-rich asteroids (the Watsonia family) makes it a stronger candidate for representing spectral slope in modeling these CAI-rich asteroids than any existing theoretical method or potential laboratory analog."},{"key":"e_1_3_1_31_2","first-page":"1338","year":"2007","unstructured":"A. Das, G. Srinivasan, Lunar Planet. Sci.XXXVIII, 1338 (2007).","journal-title":"Lunar Planet. Sci."},{"key":"e_1_3_1_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/0016-7037(93)90098-H"},{"key":"e_1_3_1_33_2","doi-asserted-by":"publisher","DOI":"10.1016\/0019-1035(89)90038-9"},{"key":"e_1_3_1_34_2","first-page":"1023","volume":"30","year":"1998","unstructured":"A. S. Rivkin, D. E. Trilling, L. A. Lebofsky, Bull. Am. Astron. Soc.30, 1023 (1998).","journal-title":"Bull. Am. Astron. Soc."},{"key":"e_1_3_1_35_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1945-5100.1995.tb01141.x"},{"key":"e_1_3_1_36_2","doi-asserted-by":"publisher","DOI":"10.1086\/311778"},{"key":"e_1_3_1_37_2","doi-asserted-by":"publisher","DOI":"10.1016\/0016-7037(95)00054-4"},{"key":"e_1_3_1_38_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1073950"},{"key":"e_1_3_1_39_2","first-page":"91","year":"1975","unstructured":"J. B. Adams, in Infrared and Raman Spectroscopy of Lunar and Terrestrial Materials, C. Karr, Ed. (Academic Press, San Diego, CA, 1975), pp. 91\u2013116.","journal-title":"Infrared and Raman Spectroscopy of Lunar and Terrestrial Materials"},{"key":"e_1_3_1_40_2","doi-asserted-by":"publisher","DOI":"10.1016\/0016-7037(75)90099-X"},{"key":"e_1_3_1_41_2","first-page":"1720","year":"2004","unstructured":"C. M. Pieters, T. Hiroi, Lunar Planet. Sci.XXXV, 1720 (2004).","journal-title":"Lunar Planet. Sci."},{"key":"e_1_3_1_42_2","doi-asserted-by":"publisher","DOI":"10.1006\/icar.2002.6856"},{"key":"e_1_3_1_43_2","doi-asserted-by":"publisher","DOI":"10.1029\/JB092iB04p0E617"},{"key":"e_1_3_1_44_2","doi-asserted-by":"publisher","DOI":"10.1029\/95JE00720"},{"key":"e_1_3_1_45_2","first-page":"585","year":"2003","unstructured":"B. E. Clark, B. Hapke, C. Pieters, D. Britt, in Asteroids III, W. F. Bottke Jr., A. Cellino, P. Paolicchi, R. P. Binzel, Eds. (Univ. of Arizona Press, Tucson, AZ, 2003), pp. 585\u2013599.","journal-title":"Asteroids III"},{"key":"e_1_3_1_46_2","doi-asserted-by":"publisher","DOI":"10.1029\/2000JE001338"},{"key":"e_1_3_1_47_2","unstructured":"This research was funded in part by NASA grants NNX06AH69G (J.M.S.) NNG05GF39G (H.C.C.) and NNG06GF56G (T.J.M. and L.M.L.) and NSF grant AST-0307688 (S.J.B.). We thank T. Hiroi for carefully collecting our spectra of CAIs and Allende samples at RELAB K. Domanik for assistance with the electron microprobe at Lunar and Planetary Laboratory and R. Binzel and two anonymous reviewers for suggestions that improved this report."}],"container-title":["Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.science.org\/doi\/pdf\/10.1126\/science.1154340","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,1,10]],"date-time":"2024-01-10T08:36:28Z","timestamp":1704875788000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.science.org\/doi\/10.1126\/science.1154340"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,25]]},"references-count":46,"journal-issue":{"issue":"5875","published-print":{"date-parts":[[2008,4,25]]}},"alternative-id":["10.1126\/science.1154340"],"URL":"https:\/\/doi.org\/10.1126\/science.1154340","relation":{},"ISSN":["0036-8075","1095-9203"],"issn-type":[{"value":"0036-8075","type":"print"},{"value":"1095-9203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,4,25]]}}}