Hi Stefano,

Thank you; this is a for-real bug, affecting all retrograde comets.
If you download

http://home.gwi.net/~pluto/lunar.dll

(about 152 KBytes), the problem will be fixed.

A little while ago, I realized that inclinations of exactly 90
degrees led to a divide by zero error. So I fixed this, and all
appeared to be well. But it meant that all prograde inclinations
(and those with inclination of exactly ninety degrees) worked, and
all retrograde orbits were off by 180 degrees. I've tested the above
with both retrograde and prograde cases. The new 'lunar.dll' works
with all of them, and the old one failed on every retrograde case.

I've also had a bug report (via private e-mail) regarding downloads
of satellite data. The problem here is that the data comes from

http://www.tle.info/data/

An hour or two ago, there was a valid 'all_tle.zip' in that folder,
and the smaller files for geosats, Iridiums, and so on had been
truncated to 112 bytes. Right now, though, 'all_tle.zip' is 172
bytes long. It is a perfectly valid .ZIP file, containing a zero-byte
'all_tle.txt'.

The tle.info site has had temporary issues before, and I _assume_
that's what we're seeing now... we may hope so, since I know of no
alternative source unless one gets an account with space-track.org.
In that case, one is reduced to downloading files from that site and
telling Guide to use them, rather than the simpler click-and-load
solution we're using now.

In the same bug report, it was mentioned that satellite magnitude
data was unavailable. It turned out that the site had moved (the data
was hosted on www.io.com, which vanished a little while ago). I've
found the new location and will update Guide accordingly.

Anyone found anything else of interest?

-- Bill