Convert Attojoules to Megajoules
Convert Attojoules (aJ) to Megajoules (MJ) instantly and accurately.
Conversion Formula
MJ = aJ × 1.000000000e-24
About Attojoules
An attojoule (aJ) is 10⁻¹⁸ J - the scale of individual X-ray photons and superconducting qubit circuits. A 1 keV X-ray photon carries 160 aJ; a visible green photon (~550 nm) carries ~0.36 aJ. Josephson junction energies in superconducting qubits are set in tens to hundreds of aJ to achieve quantum coherence at millikelvin temperatures. XRISM's cryogenic TES X-ray spectrometer resolves individual photon energies at the hundreds-of-aJ level with ~7 eV FWHM resolution. 1 aJ = 10⁻¹⁸ J = 6.242 eV.
About Megajoules
A megajoule (MJ) is 10⁶ J - the scale of fuel combustion in vehicles and kinetic energy of road traffic. Energy content: 1 L diesel ~34.9 MJ; 1 L petrol ~32.2 MJ. A 1,500 kg car at 100 km/h has KE = ½ × 1,500 × 27.78² ≈ 0.579 MJ; at 200 km/h it carries 2.31 MJ - explaining crash severity's quadratic speed dependence. A 60 kWh EV battery stores 60 × 3.6 = 216 MJ. Detonation of 1 kg TNT releases 4.184 MJ. Adults at rest metabolise ~6-9 MJ/day. 1 MJ = 10⁶ J = 239.0 kcal = 0.27778 kWh = 947.8 BTU.
Quick Reference Table
| Attojoules (aJ) | Megajoules (MJ) |
|---|---|
| 1 aJ | 1 × 10-24 MJ |
| 2 aJ | 2 × 10-24 MJ |
| 5 aJ | 5 × 10-24 MJ |
| 10 aJ | 1 × 10-23 MJ |
| 25 aJ | 2.5 × 10-23 MJ |
| 50 aJ | 5 × 10-23 MJ |
| 100 aJ | 1 × 10-22 MJ |