Life Beyond Earth

[Gregory Matthews]

Kekpler-442b is a recently discovered planet that is thought to be suitable for life.  It is located 1,200 light years away from this Earth.  Some would like to suggest that in the future we should send humans to that planet to establish human life on it.  If those humans could travel at the speed of light, which is impossible now, it would take them 1,200 Earth yeas to reach it.  If that were to be successfully attempted, what age would the people be when they reached that planet?

https://www.msn.com/en-US/news/scienceandtechnology/scientists-discover-a-planet-that-may-be-even-more-habitable-than-earth/ar-AA1no98B

The answer to our question lies in an interesting effect of living on the International Space Station.  Let us say that NASA obtained two clocks that were totally in sync with each other.   IOW, over all periods of extended time, they maintained exactly the same time.  No difference of any amount ever existed between them.  One clock remains on Earth, while the second clock it taken to the International Space Station.  one-hundred years pass and the second clock is returned to Earth.  At the time it is noted that it differs from the first clock by one second.  In short, it is one second behind the time on the first clock.  

If he second clock had been further from the Earth, it would have slowed more.  It the International Space station had been traveling faster, the second clock would have been slower.  If that second clock had been traveling at the speed of light, it would have stopped completely and 100 years later it would have reported the exact same time as it was when it departed the Earth.  

https://en.wikipedia.org/wiki/Time_dilation

NOTE:  In asking the question, I have gone beyond the information found in the two cited articles.