[meteorite-list] Re-Post: Watching meteorites fall on the Moon

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Sun Apr 24 09:16:58 2005
Message-ID: <DIIE.000000300000375F_at_paulinet.de>

On Monday, July 05, 1999, I sent this to the List:

News Update - Ramble through the journals by Professor
Chris Kitchin (Astronomy Now, July 1999, p. 8):

Lunar meteorites:

The myriads of impact craters covering the lunar surface are clear evidence
that meteorites of all sizes have hit the Moon in the past. Numerous meteors,
and more occasionally meteorites are observed hitting the Earth. Given the
closeness of the Earth and Moon, on astronomical scales, we should clearly
therefore expect meteorites to be continuing to collide with the Moon. Since
there is no atmosphere to slow them down, even small particles will hit the
surface at high velocities and produce an explosion. Could those explosions
be observed from Earth? A simple calculation shows that for a l kg meteorite,
the flash on impact would be about magnitude +7 or +8; easily visible through
a small telescope against the dark part of the Moon. In an attempt to detect
such impacts Ortiz et al. (Astron. Astrophys. 343, L57, 1999) used a CCD on
a 0.25m (10-inch) Newtonian telescope to observe an area of about three million
square kilometres of the dark part of the Moon. They observed for a total of 4.3
hours, and attempted to detect impacts by subtracting one image from another.

The result was a uniform grey except where a change had occurred between the two
exposures, when a light or dark spot would be visible. They detected five events
which could have been impacts, but these had magnitudes around +11, and the authors
cannot rule out the possibility that they are artefacts due to noise and not real
impacts. Nonetheless the idea seems to have considerable potential, and any
astronomer with a small telescope equipped with a CCD could follow it up.

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Have a nice one,

Bernd
Received on Sun 24 Apr 2005 09:16:56 AM PDT