بِسْمِ اللهِ الرَّحْمٰنِ الرَّحِيْمِ
We know from recent scientific discoveries that our atmosphere protects the Earth from not only heat rays from the sun, but also meteorites. When a meteorite enters the atmosphere it burns to ashes from the heat generated. Have a look here.
Allah says in the Qur’an:
“And We made the sky a protected shield, but they, from its signs, are turning away.” [21:32]
There is no way a man living 1400 years ago in a desert knew that the sky was a shield, from anything.
Allah knows best.