Astronomy & Astrophysics 485, L1–L4 (2008)
DOI: 10.1051/0004-6361:200809905
The Carancas meteorite impact – Encounter with a monolithic
meteoroid
J. Borovicka and P. Spurny
Astronomical Institute of the Academy of
Sciences, Fricova 298, 25165 Ondrejov Observatory, Czech Republic
Abstract. The formation of a 13-m wide impact crater by a
stony meteorite near
Carancas, Peru,
on September 15, 2007 was an unexpected event. Stony meteoroids
usually
disintegrate in the atmosphere in many pieces, each landing at low
velocity.
We present examples of well-observed fireballs, which have all
experienced atmospheric
fragmentation. Using a simple model, we find that the
Carancas meteoroid may have avoided fragmentation, if its strength
was 20–40 MPa; such a strength would be comparable to the tensile
strength
of stony meteorites, but is higher than
the strength of other observed meteoroids. We conclude that Carancas
was a rare
example of a monolithic meteoroid that was free of internal cracks.
This example demonstrates that meteoroid strength can vary
significantly
from case to case and does not depend on meteoroid size.
We estimate that the initial size of Carancas meteoroid was
0.9–1.7 m.
Our model predicts an impact velocity that was in the range 2–4 km
s-1.
Keywords: meteors, meteoroids – Earth
______________________________
back to the list of publications
next abstract
previous abstract