* Astronomy

Blobrana · L

RE: Puerto Lápice meteorite

Blobrana · L

Title: Puerto Lápice eucrite fall: Strewn field, physical description, probable fireball trajectory, and orbit
Authors: Trigo-Rodríguez J.M., J. Borovicka, J. Llorca, J.M. Madiedo, J. Zamorano, and J. Izquierdo

The fall of the Puerto Lápice eucrite occurred on May 10, 2007, at 17 h 57 m 30 ± 30 s UTC. Its daylight fireball was witnessed by hundreds of people from Spain, and produced a meteorite fall associated with a large strewn field of fragments. There were no direct pictures of the fireball, but several pictures of the fireball's train were taken from different locations in Spain. Additional theodolite calibrations of visual records were made in order to find the most probable fireball trajectory based on the available data. The shape of the meteorite strewn field was considered as well. Although the orbit of the Puerto Lápice meteoroid could not be computed due to the absence of velocity data, we assumed a likely range of geocentric velocities and computed a range of possible orbits. All solutions show that the body was in an Apollo-type orbit, with low inclination and perihelion distance just below 1 astronomical unit (AU). This is the first case that an orbit can be discussed for an HED meteorite fall.

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Blobrana · L

Title: The Puerto Lápice eucrite
Authors: Llorca, J.; Casanova, I.; Trigo-Rodriguez, J. M.; Madiedo, J.; Roszjar, J.; Bischoff, A.; Ott, U.; Franchi, I. A.; Greenwood, R. C. and Laubenstein, M.

Puerto Lápice is a new eucrite fall (Castilla-La Mancha, Spain, 10 May 2007). In this paper, we report its detailed petrography, magnetic characterization, mineral and bulk chemistry, oxygen and noble gas isotope systematics, and radionuclide data. Study of four thin sections from two different specimens reveal that the meteorite is brecciated in nature, and it contains basaltic and granulitic clasts, as well as recrystallised impact melt and breccia fragments. Shock veins are ubiquitous and show evidence of at least three different shock events. Bulk chemical analyses suggest that Puerto Lápice belongs to the main group of basaltic eucrites, although it has a significantly higher Cr content. Oxygen isotopes also confirm that the meteorite is a normal member of the HED suite. Noble gas abundances show typical patterns, with dominant cosmogenic and radiogenic contributions, and indicate an average exposure age of 19 ± 2 Ma, and a Pu-fission Xe age well within typical eucrite values. Cosmogenic radionuclides suggest a preatmospheric size of about 20-30 cm in diameter.

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