Astronomy · MPC catalog history

Which MPC circulars changed Saturn's moon count from 274 to 285 to 293?

A dated source map connecting Saturn's reported totals of 274, 285, and 293 to the Minor Planet Electronic Circulars that changed the catalog.

SOURCE BOUNDARY

The circular sequence behind the three totals

MPEC 2025-E153, E154, and E155 announced 61, 34, and 33 Saturnian satellites on 11 March 2025: 128 additions that moved the total from 146 to 274. MPEC 2026-F14 announced 11 more on 16 March 2026, producing 285. Seven Saturn circulars in the 2026-G68 through G75 block moved the catalog to 292 on 9 April; G73 concerns Jupiter.

VERSIONED RECORD

One final circular makes 293, but the row ledger still matters

MPEC 2026-M19 added S/2009 S 2 on 17 June 2026, bringing the total to 293. The evidence record resolves every provisional designation, discovery epoch, circular URL, and the distinction between the seven April irregular satellites and the Cassini B-ring moonlet added in June.

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RESEARCH TASK

Question to resolve

Which dated Minor Planet Center circulars and object designations explain Saturn's reported moon-count changes from 274 to 285 to 293?

Evidence requirements

Primary terms

MPEC 2025-E153MPEC 2025-E154MPEC 2025-E155MPEC 2026-F14MPEC 2026-M19S/2009 S 2Saturn 293 moons

Technical objective

Reconstruct each catalog transition from dated primary-source circulars and map every increment to the corresponding provisional designations.

Success condition

The answer accounts arithmetically for 274, 285, and 293, identifies the circular boundaries, and distinguishes Saturn records from neighboring unrelated circulars.

Search fingerprints

  • 11 March 2025 transition from 146 to 274
  • 16 March 2026 transition from 274 to 285
  • 9 April 2026 G68 through G75 circular block
  • 17 June 2026 M19 transition from 292 to 293

AGENT EVIDENCE INDEX

Search the dated Saturn catalog ledger

MPC circular dates, provisional designations, discovery records, and reported Saturn totals

Read task llms.txt