Distance

Space is measured in all three measures: kilometers, Astronomical Units and light years. The difference between km, Au, Ly is that km are a metric unit of length equal to 1000 meters, where as an Astronomical Unit is the distance between the sun and the earth in comparison a light year is the distance light travels in one year. Kilometer's are often used to measure a planet's diameter. Astronomical Units are used to measure the distance between planets. One Au is 150 km. Light years are used to measure distances in space. A Light year travels at 186,ooo mi/sec. One light year advances at 9,458,000,000,000 km = 6,000,000,000,000 miles.

The closest Uranus can get to Earth is 2.57 billion km. When these planets are at their most distant point they are 3.15 billion km away from each other. Depending on where Uranus and Earth are in their orbits it took voyager two 9.5 years to reach Uranus from Earth. A human being has never and will never get to Uranus. It took voyager two 9.5 years to reach Uranus; humans would not have enough food to last that long a span of time.