(When) is a conditional tool. When there is a conditional statement, there has to be an answer.
كُوِّرَتْ (wrapped up): It is rolled up, fold, wiped and thrown in the space.
This is a sign that the sun’s mission has ended so that it is removed completely. That is because the new existence that the universe is facing does not need its light or its heat.
﴾يَوْمَ تُبَدَّلُ الْأَرْضُ غَيْرَ الْأَرْضِ وَالسَّمَاوَاتُ ۖ وَبَرَزُوا لِلَّهِ الْوَاحِدِ الْقَهَّارِ﴿
(It will be] on the Day the earth will be replaced by another earth, and the heavens [as well], and all creatures will come out before Allah, the One, the Prevailing.) (Ibrahim: 48)
﴾ وَأَشْرَقَتِ الْأَرْضُ بِنُورِ رَبِّهَا﴿
(And the earth will shine with the light of its Lord,) (Az-Zumar: 69)