This is as Allah (swt) says:

 {الَّذِي خَلَقَ سَبْعَ سَمَاوَاتٍ طِبَاقًا ۖ مَّا تَرَىٰ فِي خَلْقِ الرَّحْمَٰنِ مِن تَفَاوُتٍ ۖ فَارْجِعِ الْبَصَرَ هَلْ تَرَىٰ مِن فُطُور}

([And] who created seven heavens in layers. You do not see in the creation of the Most Merciful any inconsistency. So return [your] vision [to the sky]; do you see any breaks?) (Al-Mulk-3)

The Truthful (swt) uses the word “Fatara” (to break) once in something that is fixed and another time in something that is ruined. An example of something that is fixed when Allah (swt) says:

 {الْحَمْدُ لِلَّهِ فَاطِرِ السَّمَاوَاتِ وَالْأَرْضِ }

([All] praise is [due] to Allah, Creator of the heavens and the earth,) (Al-Mulk: 3)

Meaning that Allah (swt) has created the heavens and the earth as no previous example and with precise ability, whereas, here the Truthful (swt) says regarding something that is ruined which is the sky, pointing out to the great frightening Day when the sky splits and the planets fall down so none of them will perform its duty, because Allah (swt) has taken away what made them useful. For Allah (swt) by His perfectibility gives a thing of the characteristics that make it suitable for what it was created for, so let no human think that he has gone outside his creator’s (swt) ability.

Of course, it does not break apart or split by itself but by order from its creator Allah (swt), as when Allah (swt) says:

 { إِذَا السَّمَاءُ انشَقَّتْ}

(When the sky has split [open]) (Al-Inshiqaq: 1)

This saying shows that as soon as the sky hears the order from Allah (swt) to split open it replies immediately and obeys the order to split open. The sky understands Allah’s (swt) order, He who created it, and will break apart for a great command that is the Judgement day and the end of this life.