Praise be to Allah, and may peace and blessings be upon the Messenger of Allah.
The conditions of the Day of Judgment will be different from the conditions of this world. Therefore, it is not correct to measure what will happen in the Hereafter according to the laws and structure that we know in our present world. Allah تعالى says:
﴿On the Day when the Earth will be replaced by another earth, and likewise the heavens﴾ [Ibrahim: 48].
Thus, the Earth and the heavens will undergo transformation, and the state of the universe on the Day of Judgment will be different from its state in this world.
As for the saying of Allah تعالى:
﴿And when the stars are scattered﴾ [Al-Infitar: 2],
some scholars interpreted being scattered as falling and dropping down, while others stated that what is meant is that the stars will become separated, leave their orbits, and that the order in which they existed will be disrupted.
According to the interpretation of falling, it does not necessarily mean that they will fall onto the Earth. They may be scattered throughout the space that formerly contained the Earth and other celestial bodies, and this may be among the matters of the unseen whose details we do not know.
Moreover, the word “scattered” in its original sense indicates separation and dispersal. Thus, what may be intended is that the stars will become separated and leave their positions and orbits after having been orderly within the system known to us.
Therefore, it is not correct to object to the verse on the basis of the enormous sizes of the stars or to ask where they will fall. The verse speaks of the transformation and collapse of the entire cosmic system and the alteration of its conditions, rather than the stars falling according to the laws and circumstances that we know in this world.
Nor does the verse necessarily specify the fate of the Earth in detail. Likewise, it is not correct to assert exactly how these unseen events will occur without evidence.
In conclusion, the verse indicates that the cosmic system will undergo a tremendous transformation on the Day of Judgment, and the stars will be scattered and their established order will be disrupted. The exact manner in which this will occur is part of the unseen, and we should not determine its details without evidence.
And Allah تعالى knows best.