[Neocp_artsats] C44C831 = junk; three other NEOCP artsats recently removed

[Bill Gray]

    First,  some good news : I just learned,  from

https://www.astronomy.com/science/astronomers-just-deleted-an-asteroid-because-it-turned-out-to-be-elon-musks-tesla-roadster/

    that "the MPC is collaborating with JPL on a system to better detect 
artificial objects that aren't in Earth orbit".  Sounds like an 
excellent idea to me.

    C44C831,  currently on NEOCP,  has a solid 2.7-day orbit (not good 
enough for me to make TLEs for it,  but enough to make me think it'll 
get found again).

    CCT8E72 got a decent arc (21 hours) from four sites,  enough to show 
that it was an ETBO.  At H=34.2,  it's one of the smaller ones :

https://www.projectpluto.com/pluto/mpecs/cct8e72.htm

    This is also in a higher (2.9-day) orbit.  Combine this with CCNT4U2 
from earlier this month,

https://www.projectpluto.com/neocp2/mpecs/CCNT4U2.htm

    and I'm seeing an ugly trend toward multi-day ETBOs.  Previously, 
the only one we had was Multijunk.  These are very annoying,  hard to 
predict objects that move slower than the one-day junk we're used to 
seeing.  I assume some higher-orbiting object lost its insulation.  This 
could be a confounded nuisance.

    Also on NEOCP were xkos477 = Gaia;  we now have good ephems for this 
object and should avoid further trouble.  C44AXX1 was the separating 
piece between Blue Ghost and Hakuto-R,  2025-010C.  It'll re-enter over 
South America at latitude ~41 S on 2025 March 15 at noon UTC,  plus or 
minus about half an hour (meaning it could end up in the Atlantic or 
Pacific).  I expect we'll get enough data to provide a solid re-entry 
prediction well before then,  enough to tell people where to look for it.

    We now have good trajectories for it,  Hakuto-R,  Blue Ghost,  and 
the Falcon 9 upper stage.  The latter will remain in high earth orbit 
for at least the next few months,  but should eventually hit the earth 
or moon or be ejected into an heliocentric orbit.

-- Bill