Physics / Astronomy
Speed of Light
Calculate how far light travels in any time, or how long light takes to cross any distance.
Cosmic Distance Reference
${[["Moon to Earth","1.28 seconds","384,400 km"],["Sun to Earth","8.32 minutes","149.6 million km"],["Mars (avg)","~12.5 minutes","225 million km"],["Pluto (avg)","~5.5 hours","5.9 billion km"],["Nearest star (α Centauri)","4.24 years","4.01×10¹³ km"],["Milky Way diameter","~100,000 years","~9.46×10¹⁷ km"],["Andromeda Galaxy","2.537 million years","2.4×10¹⁹ km"]].map(([p,t,d])=>`
${p}${t}${d}
`).join("")}
c = 299,792,458 m/s ≈ 3×10⁸ m/s · 1 light-year ≈ 9.461×10¹⁵ m
1 AU = 1.496×10¹¹ m · 1 parsec = 3.086×10¹⁶ m