Hi all;

Just to put some numbers to the discussion I took a look at 1973-2006.

No special reason, I just have a file of planetary positions for that period.

For each day I computed the angle between sun and jupiter and sun and saturn.
If the angle was <= 3 or >= 178 and <= 180 an aspect day was counted.

Then I looked at the quake file and counted a hit for quakes >= a minimum, either 6 or 7.

The results are summarized below.

Magnitude 6.0 and up.
There were 12418 days examined.
There were 3505 quakes found.
There were 714 planetary aspect days.
There were 194 quakes on aspect days.
Chances of an aspect day are .057
Fraction of quakes captured: .055

Magnitudes 7.0 and up.
There were 12418 days examined.
There were 489 quakes found.
There were 714 planetary aspect days.
There were 21 quakes on aspect days.
Chances of an aspect day are .057
Fraction of quakes captured: .043

As you can see, results are a bit worse than chance.
Some of the values were chosen arbitrarily as I don't know what he was using.

Roger