How long will it take to get to earth from Neptune?

Answer 1

Neptune, the 8th planet from the Sun, orbits at an average distance of about 30AU. Each Astronomical Unit is the distance from the Sun to the Earth, about 93,000,000 miles. This works out to be 500 light-seconds, or 8.3 light-minutes, from the Sun to the Earth.

Neptune is 30 times more distant, so when the Earth and Neptune are on the same side of the solar system, we are about 29 AU from Neptune, while if we are on opposite sides, it is 31 AU.

So light takes between 14,500 seconds to 15,500 seconds to get from Earth to Neptune. Since the speed of light is (we believe!) an absolute limit, nothing material could get there in less time.

How long would it take HUMANS to travel from Earth to Neptune? Right now, there is no possible way to send a person there. Even a robot probe like the New Horizons mission to Pluto, would take a dozen years or more to arrive there. As technology progresses, we will eventually be able to travel there, but I would not expect the first human to arrive in cis-Neptunian space until the year 2150 at the earliest. And that's only if we figure out some excellent reason for going there at all.

Answer 2

Depends on your means of transport. I wouldn't recommend going by foot, as it may take a while, but driving there or even cycling are both pretty doable. You can count on travelling at least a few years tho so make sure you pack enough clean underwear! ;)

Notes: This gives you some idea of the time. It took the "Voyager 2" probe about 12 years to get to Neptune from Earth.

Answer 3

Assuming a ship with appropriate provisions, and that could go as fast as probes we've already sent there, a little over 12 years.