18:90 SAHIH INTERNATIONAL Until, when he came to the rising of the sun, he found it rising on a people for whom We had not made against it any shield.
The story of Dhul Qarneyn states that Alexander travelled to the setting and rising of the sun. But he met people with no protection from the sun, this seems to be a condradiction stating the sky protects people. Even if you were to assume that they had no sky. They would of been killed without a sky or an atmosphere.Please note the protection doesnt have to be sky. It could also be trees, mountains and etc for those assuming this is one miracle of the quran that the sky protects against the sun.However the sky does offer some protection from it. But the verse doesnt speak about the sky so it seems the author had no idea that the sky offered some protection.
From Ibn Kathir: (for whom We (Allah) had provided no shelter against the sun.) meaning, they had no buildings or trees to cover them and shade them from the heat of the sun. Qatadah said, "It was mentioned to us that they were in a land where nothing grew, so when the sun rose they would go into tunnels until it had passed its zenith, then they would come out to go about their daily lives and earn themselves a living.''