The speed of light is about 300,000 km (or 300,000,000 m) per second, so in a year, light travels 300,000×3,600 (seconds in an hour) ×24 (hours in a day) ×365 (days in a year) = 9.4608×1012,
then multiply this by 500 9.4608 × 10 12 × 500 = 4730400000000000 (or 4.7304 × 10 15
When t=time, d=distance and s=speed,
t=d/s
4730400000000000 km /618 km/s=7654368932038.835 seconds
Divide this by seconds in an hour, hours in a day and days in a year
7654368932038.835/3,600×24×365
= 242718.447 years
