Jim, Any specifics on which Apollo missions the Saturn V SIVB stages left in high Earth orbit were from? It might allow some "back of the envelope" trajectory propagations to be done to see what the (general?) specifics of the resulting perturbed heliocentric orbit might be. Also, do you know where the list of manmade heliocentric orbit objects might be made available? TIA, and sorry if this is a little bit off topic. Cheers, Daryl Bahls In a message dated 99-09-05 17:26:31 EDT, Jim Scotti wrote: << Subj: Re: mystery object....1991VG Date: 99-09-05 17:26:31 EDT From: jscotti@LPL.Arizona.EDU (Jim Scotti) To: satcom@cybase.co.uk (John locker) CC: seesat-l@blackadder.lmsal.com Hi John, As the discoverer of said object, I'll give you the brief summary (more can be found by visiting the list archives as this object has come up a few times in the past). As you can see from the circular that you quoted, 1991 VG was discovered by me on Nov. 6, 1991. [deletia] I think the speculation that it is manmade is only that - the probability that we would find such an object is rather low considering the number of things we've ejected onto heliocentric orbits. 1991 VG made an approach to the Earth's vicinity in 1973 or 1974 and before that was before Sputnik, so there's one window of opportunity for a launch. [deletia] I personally believe it's an asteroid as the likelyhood is much higher, but if it's man-made, I think it's more likely to be one of the Saturn V SIVB stages left in high Earth orbit during Apollo (there were 2, I think that weren't impacted on the moon or ejected directly into solar orbit), and a few years perturbations would be just about right to eject it into solar orbit. BTW, Back at that time, I was sent a list of the man-made objects in heliocentric orbit and I was surprised at just how many objects were on that list. Besides active spacecraft (or formerly active...), there are many rocket stages. Lots of historically significant objects out there to be retrieved and put in museums someday! Jim. >>