Current Nearest possibly habitable planet other than in our solar system.
A: 20.3 light years away
current fastest record for spacecraft velocity :
A: 150,000 mph
the speed of light : roughly 186,000 miles per second
to get our fastest spacecraft speed into the same units of seconds, as the speed of light : (150,000mph ÷ 60) ÷ 60) =
A: 41.6 miles per second is the fastest an unmanned human spacecraft has ever travelled.
Dividing the speed of light in miles per second by our fastest speed in miles per second
186,000 mps ÷ 41.6 mps = we currently are able to travel in space 4471.15 times slower than the speed of light.
so how long would it take to travel one way to a star 20.3 light years away ?
4471.15 × 20.3 light years = 90,764.345 years to reach a solar system only 20.3 light years away at a speed of 150,000 mph ?
ok lets enhance that situation by saying theyre ight be a habitable planet in nearby alpha centauri 4.3 light years away were still talking.
4471.15 × 4.3 = 19,225.945 years of travel
to make this alpha visiting journey even a 100 year project would involve travelling at a velocity of 7998 miles per second which with accelerating and breaking slowly would no doubt involve going at some speeds faster than that at some point.
basically at a speed of 28,792,000 mph, anyone fancy manouevering at that speed ?
being that speed of light per annum is 6,69,600,000 mph.