[namrog84]

https://www.iau.org/public/themes/naming/

It's initially given a temporary name prior to the now official name.

2018 CN41

Means it's the 41st object identified in the first half of February in 2018.

A is first half of jan. B is 2nd half. Etc.. then the iteration in that section

[crusty]

I think the question is, how does the 41st object to be discovered in 2018 get that name in 2025?

Clearly there's a missing link to this, as in some guy in a field "finds" an object, submits it, it gets added, it gets identified, it gets removed, and it's actual designation is then used in write-ups as if that name were the one in use before it was identified as not being an object discovered in 2025.

For accuracy, or should say 2025 CN2 (or whatever), aka 2018 CN41, was removed from the database.

[spenczar5]

Ooh, I know this one! I worked on historical asteroid observations categorization and precovery for a few years.

The MPC has many observations of unidentified moving object candidates. These are called “tracklets” and come from pairs of observations of the same patch of the sky by the same observatory, separated (typically) by a few minutes.

The “isolated tracklet file”, or ITF, is a catalog of all of these unidentified moving objects.

When an identification is made and submitted to the MPC, the MPC back-projects the orbit and checks the ITF for any past observations which might have actually been of this newly identified object.

Then, the designation’s timestamp is of the first matching observation. So in this case the ITF had an observation from back in 2018.

Occasionally, two “objects” turn out to be the same actual physical object, but we learn late. In this case, the MPC does maintain a list of “aliases” of the object, so you might get that “aka” list. But that is not quite what happened here.

[wbl]

I'm not an expert but my understanding is it takes multiple observations to pin down an orbit and be sure it isn't an existing object. Those observations can be very chance driven.

[walrus01]

The year and number designator is for known man made object launches. All satellites get a COSPAR ID

It's done in sequential order.

https://en.wikipedia.org/wiki/International_Designator

Even top secret NRO launches get a designator, since it's impossible to hide the launch itself, but its orbital activity and TLE might not be obvious once in space.