Light hour

From Citizendium, the Citizens' Compendium

The light hour is the distance that the light travels in vacuum in one hour and so is a unit of distance.

Similar units are the light second, light minute, light day, light week, light month, light year.

Contents 1 Numerical value 2 Comparison to other Units 3 Distances in Light hours[5] 4 Notes

Numerical value

As opposed to the light year, whose value more or less depends on the definition of year, the value of the light hour is defined exactly.

• velocity of light in vacuum: 299,792,458 m/s ^[1] (meters/second)
• 1 hour = 60 minutes = 3600 seconds
• 1 light hour = 1,079,252,848,800 m = 1.0792528 * 10¹²m

Comparison to other Units

• 1 AU = 0.14 light hours
• 1 light hour = 1,079,252,848.800 km
• 1 light hour = 638,481,190.100 mi^[2]
• 1 light hour = 3,540,855,803,149.606 ft^[3] = 3.5408558 * 10<sump>12</sup> ft
• 1 light hour = 1,180,285,267,716.535 yd ^[4] = 1.1802853 * 10¹² yd

Distances in Light hours^[5]

• the maximum distance between sun and Merkur is about 57.9 Mio km or 0.05 light hours
• the maximum distance between sun and Venus is about 108.2 Mio km or 0.10 light hours
• the maximum distance between sun and earth is about 149.6 Mio km or 0.14 light hours
• the maximum distance between sun and Mars is about 227.9 Mio km or 0.21 light hours
• the maximum distance between sun and Jupiter is about 778 Mio km or 0.72 light hours
• the maximum distance between sun and Saturn is about 1427 Mio km or 1.32 light hours
• the maximum distance between sun and Uranus is about 2870 Mio km or 2.66 light hours
• the maximum distance between sun and Neptun is about 4496 Mio km or 4.17 light hours
• the maximum distance between sun and Pluto is about 5946 Mio km or 5.51 light hours
• the maximum distance between sun and Sedna^[6] is about 133,593 Mio km or 123.5 light hours

Notes