Convert Sidereal Months to Megayears
Convert Sidereal Months (sid.mo) to Megayears (Ma) instantly and accurately.
Conversion Formula
Ma = sid.mo × 7.480416898e-8
About Sidereal Months
The sidereal month = Moon's orbital period relative to the fixed stars = 27.3217 days = 2,360,591.6 s - the shortest lunar month. It is ~2.21 days shorter than the synodic month (29.53 d) because Earth advances ~27° along its orbit in the same period; the Moon must travel further to re-align with the Sun. Used in GPS orbit design, tidal modelling, and lunar laser ranging. 1 sid.mo = 27.3217 d.
About Megayears
A megayear (1 Ma) = 10⁶ yr ≈ 3.156 × 10¹³ s - the timescale of geology and tectonic evolution. The K-Pg mass extinction at 66.0 Ma; Cambrian explosion ~538.8 Ma; Great Oxygenation Event ~2,400 Ma. Plate motion at 2-10 cm/yr = 200-1,000 km per Ma (Atlantic ~3,000 km wider since Pangaea rifting ~200 Ma ago). Background extinction rate measured in extinctions per million species-years. 1 Ma = 10⁶ yr.
Quick Reference Table
| Sidereal Months (sid.mo) | Megayears (Ma) |
|---|---|
| 1 sid.mo | 7.48 × 10-8 Ma |
| 2 sid.mo | 1.496 × 10-7 Ma |
| 5 sid.mo | 3.74 × 10-7 Ma |
| 10 sid.mo | 7.48 × 10-7 Ma |
| 25 sid.mo | 1.87 × 10-6 Ma |
| 50 sid.mo | 3.74 × 10-6 Ma |
| 100 sid.mo | 7.48 × 10-6 Ma |