Fun fact.
Only around 0.0000001% of the map of No Man’s Sky has been explored: it would likely take over a million years for the entire human race combined to get over 1%.
That statistic is mind-boggling, and mathematically, it is completely accurate. The universe of No Man's Sky contains 18 quintillion planets (specifically, 18,446,744,073,709,551,616).
The game does not store pre-made maps. It uses mathematical algorithms to generate planets instantly as you approach them. Spending just one second on every planet would take you roughly 585 billion years to see them all.