(advancements in technology aside)
Recently, astronomers from Middlebury College discovered one of the fastest-moving large objects ever observed, designated RX J0822-4300.
They calculated the neutron star is moving about 3 million miles per hour and has already traveled 20 light years. "It's so far away that the apparent motion we see in five years is less than the height of the numerals in the date on a penny, seen from the length of a football field," said Frank Winkler.
Since light moves at about 671 million miles per hour, the star is traveling at slightly under one-half of 1 percent of light speed.
It would take the star 20 million years to cross our galaxy from one end to the other, another 350 million years to reach the next-closest galaxy to ours.
Observation of this star tells us it is physically possible to accelerate a very heavy object to a measurable fraction of light speed; some physicists had contended that might always be impossible. So let's suppose humanity someday builds a spaceship capable of one-half of 1 percent of light speed.
A ship moving at half of 1 percent of the speed of light could reach Mars in about 10 hours and be at Saturn in about a day, but would still be a rowboat compared with cosmic distances -- requiring 800 years to reach the nearest star to our sun and 6 million years to reach the galactic center.