Re: [find_orb] Re: Update fixed

Bill J Gray Mar 14, 2010

Hi Peter,

I think you've got a case where Find_Orb is computing planetocentric
elements, which don't "fit" into the mpcorb format. So Find_Orb puts
the elements into 'virtual.txt' instead, in a different format.

Go into Settings and tick the "Heliocentric Only" box, and try
again, and you'll instead get heliocentric orbits in 'mpcorb.dat'.

What Find_Orb ought to do in these cases is to add planetocentric
elements to 'virtual.txt' _and_ heliocentric ones to 'mpcorb.dat'.
I'll make that fix. But using "heliocentric only" will get you in
business for the nonce.

Ideally, we'd have a standardized format for exchanging orbital
elements. The MPCORB one is suitable only for heliocentric, elliptical
orbits with asteroid magnitude parameters. Generalizing it, and
allowing for additions such as uncertainty parameters and non-gravitational
forces and such, would be a Good Thing. I've pestered MPC about this
in the past, and may do so again.

-- Bill