How fast can you travel in outer space?
What percentage of the speed of light can we travel?
Albert Einstein’s special theory of relativity states that photons—or particles of light—travel at a constant speed of 670,616,629 miles per hour. As far as we know, nothing can travel faster than this. But across the universe, particles are often accelerated to 99.99 percent the speed of light.
How long would it take for a spaceship to travel one light year?
This duration is a bit of a problem, as it makes space exploration a painstakingly slow process. Even if we hopped aboard the space shuttle discovery, which can travel 5 miles a second, it would take us about 37,200 years to go one light-year.
Will space travel ever be possible?
Intergalactic travel for humans is therefore possible, in theory, from the point of view of the traveller. Accelerating to speeds closer to the speed of light with a relativistic rocket would allow the on-ship travel time to be drastically lower, but would require very large amounts of energy.