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Re: Possible Meteorite Fall in Australia

Martin Horejsi writes:
>I was under the impresson that we had seismic data of meteorite impacts
>collected on the moon.  

Yes, that is correct.  Four of the Apollo missions carried seismometers.
Several moonquakes were detected, the largest at about 2 on the Richter
scale.  Some of the tremors detected were from meteroid impacts.  There was
also a regular pattern of moonquakes occuring every 14 days, which correlated
with when the Moon was at its closest and greatest distance from the Earth.
The moonquakes have different behaviour from earthquakes. An earthquake
tends to start suddenly and last a couple of minutes, while a moonquake will 
slowly build up and last about an hour.

>In fact, thought that there were some deliberate
>experiments carried out where moon-orbiting debris were crash-landed on the
>moon near a seismic recorder in order to note the seismic signature of an
>impact.

The Lunar Orbiters were intentionaly crashed on the Moon to ensure they
would be no interference with them with Apollo, and I think this is
what you are referring to.  

The Viking spacecraft also carried seismometers to Mars.  The Viking 1
seisometer failed to deploy, but Viking 2 detected a 2.8 Richter marsquake.

Ron Baalke