Convert Barns to Square Megameters
Convert Barns (b) to Square Megameters (Mm²) instantly and accurately.
Conversion Formula
Mm² = b × 1.000000000e-40
About Barns
A barn (b) is a unit of area used in nuclear and particle physics to measure effective cross-sections of atomic nuclei and particle interaction probabilities. Equal to 10⁻²⁸ m² (10⁻²⁴ cm²), it was humorously named during the Manhattan Project - physicists joked that uranium nuclei were 'as big as a barn' at the subatomic scale. Particle physics experiments at accelerators like CERN report cross-sections in millibarns (mb), microbarns (μb), nanobarns (nb), and femtobarns (fb).
About Square Megameters
A square megameter (Mm²) equals the area of a square with sides of one million meters - 10¹² m², or one trillion square meters. At this scale we describe major geographic and planetary regions. The entire land surface of Earth is about 149 Mm², the Indian Ocean covers roughly 70 Mm², and the Sahara Desert spans approximately 9.2 Mm². Square megameters provide a convenient scale for comparing continent-sized areas without resorting to hundreds of millions of square kilometers.
Quick Reference Table
| Barns (b) | Square Megameters (Mm²) |
|---|---|
| 1 b | 1 × 10-40 Mm² |
| 2 b | 2 × 10-40 Mm² |
| 5 b | 5 × 10-40 Mm² |
| 10 b | 1 × 10-39 Mm² |
| 25 b | 2.5 × 10-39 Mm² |
| 50 b | 5 × 10-39 Mm² |
| 100 b | 1 × 10-38 Mm² |