Weigel, A. | Search NASA

NASA NTRS2000

Leonids: Did They Make it to Earth?

On the morning of November 18. 1998, following the spectacular Leonid meteor shower, one of us (S. De) found particles spread over the roof terrace in a residence in Baruipur. a suburb of Calcutta, India. Considering the time and location, these particles possibly derived from the meteor shower, although the fall was not observed. Other particles collected in connection with the Leonid showers in different parts of India proved to be of terrestrial origin.

Weigel, A.↗

NASA NTRS1993

The Xe-Q in lodranites and a hint for Xe-L. FRO90011 another lodranite?

The Lodran achondrite contains about one-quarter metallic Fe/Ni, two-thirds olivine and pyroxene, some troilite, plus minor phases. In a previous study we demonstrated that Lodran and three other lodranites - LEW88280, Yamato-791491, and MAC88177 - yield the same cosmic-ray exposure age of a few million years, suggesting that they originate from the same parent body. In the present work we show that the mineral phases of Lodran contain large concentrations of planetary-type but no solar-type trapped noble gases. Surprisingly, the highest concentrations were observed in the Fe/Ni-phase (e.g. 1520 x 10(exp -12) cc STP per g (132)Xe). A large fraction of the trapped gas is released between 1200 C and 1400 C. The Xe isotopic pattern is similar to that of Xe-Q. The 1400 C fraction of the Fe/Ni-phase shows excesses of (124)Xe, (126)Xe, and (128)Xe similar to Xe-L (pre-solar Xe enriched in the light isotopes) that has, until now, only been observed in combination with Xe-H (pre-solar Xe enriched in the heavy isotopes).

Eugster, O.↗