Light distance (or radio distance) to Jupiter


Jupiter is about 4 AU from the Earth at opposition (that is when Earth and Jupiter are aligned on the same side of the Sun)

1 AU = 150,000,000 kilometers

So this (4 AU) is about 600,000,000 kilometers

Light travels at 300,000 kilometers/sec

Therefore, the time it takes light (or radio waves) to travel from the Earth to Jupiter (or vice-versa) when the two planets are closest is

Remember, this is when the planets are closest to one another.
Any other time it will take even longer.