@Article{Matzel:2010, author = {J.E.P. Matzel, H.A. Ishii, D. Joswiak, I.D. Hutcheon, J.P. Bradley, D. Brownlee, P.K. Weber, N. Teslich, G. Matrajt, K.D. McKeegan and G.J. MacPherson}, title = {Constraints on the Formation Age of Cometary Material from the NASA Stardust Mission}, journal = {Science}, booktitle = {}, editor = {}, publisher = {}, month = {}, year = {2010}, volume = {328}, number = {}, pages = {483--486}, note = {}, annote = {}, keywords = {}, url = {http://sims.ess.ucla.edu/pdf/Matzel_et_al_2010.pdf}, doi = {10.1126/science.1184741}, isbn = {}, abstract = {We measured the $^{26}$Al-$^{26}$Mg isotope systematics of a \sim5-micrometer refractory particle, Coki,returned from comet 81P/Wild 2 in order to relate the time scales of formation of cometary inclusions to their meteoritic counterparts. The data show no evidence of radiogenic $^{26}$Mg and define an upper limit to the abundance of $^{26}$Al at the time of particle formation: $^{26}$Al/$^{27}$Al $<$ 1 $\times$ $10^{-5}$. The absence of $^{26}$Al indicates that Coki formed $>$ 1.7 million years after the oldest solids in the solar system, calcium- and aluminum-rich inclusions (CAIs). The data suggest that high-temperature inner solar system material formed, was subsequently transferred to the Kuiper Belt, and was incorporated into comets several million years after CAI formation.}, } %%%%% 2011 Publications %%%%%