Supernova Ending Explained [SPOILER!]

SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!

SPOILERS AHEAD

Supernova Plot Summary and Synopsis

Sam (Academy Award winner Colin Firth) and Tusker (Academy Award nominee Stanley Tucci), partners of twenty years, are traveling across England in their old camper van visiting friends, family and places from their past. Following a life-changing diagnosis, their time together has become more important than ever until secret plans test their love like never before.

Source: Wikipedia (CC BY-SA 3.0).