Convert Milliarcseconds to Arcminutes
Convert Milliarcseconds (mas) to Arcminutes (′) instantly and accurately.
Conversion Formula
′ = mas × 1.666666667e-5
About Milliarcseconds
A milliarcsecond (mas) is one thousandth of an arcsecond - approximately 4.848 × 10⁻⁹ rad. It is the standard unit of precision astrometry. The ESA Hipparcos satellite measured stellar positions to ~1 mas; its successor Gaia achieves 7-100 µas for bright stars. A parallax of 1 mas corresponds to a distance of 1 kiloparsec (3,260 light-years). Very Long Baseline Interferometry (VLBI) resolves well below 1 mas, imaging structures around supermassive black holes. 1 mas = 10⁻³ arcseconds ≈ 4.848 × 10⁻⁹ rad.
About Arcminutes
An arcminute (′) is 1/60 of a degree - π/10,800 rad ≈ 2.909 × 10⁻⁴ rad. One arcminute of latitude equals exactly one nautical mile (1,852 m), which is the origin of the nautical mile unit. The Moon and Sun both subtend ~30 arcminutes in apparent diameter - the coincidence exploited in total solar eclipses. Human 20/20 visual acuity resolves letters 5 arcminutes tall at 6 m. Binocular and telescope apparent fields of view are quoted in arcminutes. 1′ = π/10,800 rad ≈ 0.01667° ≈ 290.9 µrad.
Quick Reference Table
| Milliarcseconds (mas) | Arcminutes (′) |
|---|---|
| 1 mas | 1.667 × 10-5 ′ |
| 2 mas | 3.333 × 10-5 ′ |
| 5 mas | 8.333 × 10-5 ′ |
| 10 mas | 0.000166667 ′ |
| 25 mas | 0.000416667 ′ |
| 50 mas | 0.000833333 ′ |
| 100 mas | 0.00166667 ′ |