Chang’e 6: a retained historical case#
The Chang’e 6 case is LunarTrace’s trust exemplar. It demonstrates how to preserve useful historical findings without inventing the original row-level evidence that was not retained.
Event anchor and its limits#
The admitted implementation basis records the Chang’e 6 landing anchor at 2024-06-01T22:23:00Z, latitude approximately -41.6385°, and longitude 206.0148° E.
The supplied historical anchor does not establish its latitude convention or named reference frame. The exact numerals must not be silently upgraded into a more strongly qualified spatial assertion. The Lab’s user-defined planetocentric starter is a separate research reference, not a modification of this record.
What was retained#
Historical quantity |
Retained value |
|---|---|
PRE observations |
14 |
POST observations |
39 |
Evaluable temporal pairs |
546 |
V1 frontier |
7 |
V2 frontier |
26 |
V3 frontier |
71 |
V4 frontier |
102 |
The protocol variants are explicitly defined in Event-conditioned comparison methodology. The retained reference pair is reported as dominated under V1/V2 and retained under V3/V4. That demonstrates sensitivity to the active objectives; it is not an accuracy score and does not establish V3 or V4 as universally correct.
Reference identities#
Contextual role |
Publication identity |
Retained PDS identity |
|---|---|---|
PRE |
|
|
POST |
|
|
Two real ODE browse assets are retained with expected byte identities. They are REFERENCE_ONLY and UNALIGNED. Independent display and byte checks are supported. Registered comparison, common cropping, photometric comparability, difference imagery, and surface-change or causal claims are not established.
What was not retained#
The original observation rows and original pair rows are unavailable. Therefore the product does not provide:
a reconstructed historical observation table;
a 546-point empirical pair scatterplot;
original row-level timestamps or footprints;
exact historical domination witnesses;
independent compiler replay from those missing original rows.
The absence of those representations is intentional. Aggregate arithmetic cannot recover the original scientific population.
Historical currentness#
The admitted historical basis contains an archive indexed-through watermark of 2026-05-15T23:57:58.104Z. That is a property of the retained basis, not a promise about today’s archive. The product does not fabricate an original query timestamp or raw-response ledger that was not retained.
What a new Lab search means#
A query near the landing area retrieves a new population under the Lab’s current source scope and budgets. It may have real rows, acquisition timestamps, and footprints and can support exploratory pair analysis relative to that capture.
Even if a count happens to equal a historical count, that numerical match does not establish population identity or historical replay. Keep the two objects separate:
Historical Study |
New Lab discovery |
|---|---|
Retained reported aggregate |
Newly captured source metadata |
Original rows unavailable |
Retrieved rows available within stated limits |
Historical basis/currentness |
New query receipt; Lab horizon currently unknown |
Stable record |
Editable exploration |
The scientific lesson#
A mature tool should show more detail when more evidence exists and less when it does not. Chang’e 6 tests that discipline while remaining useful for method inspection, reference evidence, provenance, and claim-level review.