[eternalban]

Alright, so J'Kaziof [1] actually lives on a nearby planet in Cygnus. This was/is a tragic event that whiped out J'Kaziof's home planet. Luckily, they had super duper advanced technology with spaceships that could reach c * .99999...

J'Kaziof witnessed this event when s/he was n seconds [old] per their atomic clocks, and immediately set out in our direction.

What is the age of J'Kaziof in seconds when s/he arrives on Earth?

[p.s. assume their ships can instantanously accelerate to c and slow down to 0 from c.]

[p.s.s. In the year of our lord 222 here on Terra, Bardesanes of Edessa [2] went to meet his maker. Let's just say he passed away at the exact moment of J'Kaziof uttering 'make it so' to his 1st officer.]

[1]: http://www.scifiideas.com/alien-name-generator/

[2]: https://en.wikipedia.org/wiki/Bardaisan

[daveguy]

Unless he lives for 1800 years he's not going to make it to earth?

[eternalban]

No, J'Kaziof's and his fellow travellers's clock will slow down to a crawl relative to ours.