'In Development' update posted

Bill Gray Aug 18, 2013

Hi all,

I've posted yet another 'in development' update at

http://www.projectpluto.com/pluto/devel/find_orb.htm

Two new improvements are mentioned: a fix to the impact lat/lon
bug that Filip Fratev pointed out on this list recently, and the
ability to use the new JPL DE-431 ephemeris.

The new ephemeris is about a 2.7 GByte download, and is not
especially useful to most of us. However, it covers the years
-12000 to +17000, so it can be _very_ useful if you're interested
in the very long-term behavior of an object. In particular, Tomas
Vorobjov asked about the MOID for the TNO 2012 HH2. As Leonid
Elenin pointed out, you can get MOIDs for eight planets (*) by
looking at the file 'elements.txt'. (Find_Orb always computes
all eight MOIDS, but only displays those that are suitably
small. For Neptune, any MOID greater than one AU is deemed to
be "uninteresting".)

Anyway. With DE-431, it would be possible to see if any
close approaches occur over the time span -12000 to +17000,
and to see just how stable the motion would be over that time
frame. This can also be useful if you're wondering if a given
object is really a Neptune or Uranus Trojan, for example.

If you're interested in DE-431 but find a 2.7 GByte download
to be a problem, please contact me privately. I may burn some
DVDs and mail them out if there's interest. The "payment"
requested would be that, after receiving and copying the
disk, you mail it to the next person who wants a copy.

-- Bill

(*) I'm not especially interested in "how many planets" there
"really" are.