Allah SWT created the heavens and the earth 6 (six) times. Allah SWT says in the Qur'an:
And verily, We created the heavens and the earth and what is between them in SIX days, and We did not feel tired in the least.
(Surat Qaf: 38).
Allah SWT created the heavens and the earth 6 (six) times at the same time, so there is no which is first and which is later! Both were created at the same time!
Period I
At first, the sky was smoke and the earth was dust, the two of them coalesced to form smoke that collects dust (Scientists know it by the name "Nebula").
The Word of Allah SWT:
Then He went to the sky and it was still smoke,
Then He said to him and the earth, “Come, both of you, at my commandments, obediently or compelled.
The two replied, “We came obediently.
(Surah Fushshilat: 11)
Period II
The smoke continues to collect dust and gets denser, the temperature continues to increase to tens of millions of ° C (Celcius), and in the end, there is a nuclear fusion reaction in it (Big Bang).
Allah SWT says:
And do the disbelievers not know that the heavens and the earth were formerly one, then We separated them; We made every living thing out of water; then why do they not believe?
(Surat al-Anbiya': 30).
As a result of the explosion, the heavens and the earth were separated and the sky was getting farther and farther away.
The hottest core of the explosion became the sun, while the condensed dust became the planets, including the earth. And with the sun and the rotation of the earth, it causes day and night.
*He raised his building (the sky) and perfected it.
and He made the night pitch black,
and make the day bright.
(Surat an-Nazi'at: 28-29)
**Furthermore, Allah SWT perfected the creation of the earth in the next four (4) periods so that the earth was suitable for human habitation.
**
Allah SWT says:
And He created in him solid mountains above him.
And then He blesses, and He prescribes food (for its inhabitants) in FOUR times, sufficient for (fulfilling the needs of) those who need it.
(Surah Fushshilat: 10)
More specifically the four periods as the Word of Allah SWT in Surah An-Nazi'at:
Period III
*Namely: The formation of the continents on earth.
And the earth after that He spread out.
(An-Nazi'at: 30)
Period IV
Namely: The creation of water and plants on earth.
He brought out of it its spring and its vegetation.
(An-Nazi'at: 31)
Period V.
Namely: The formation of mountains on earth.
And the mountains he fixed firmly
(An-Nazi'at: 32)
Period VI
Namely: The creation of animals, and the creation of humans to occupy the earth.
For your pleasure and your livestock.
(An-Nazi'at: 33)
Subhanallah!
Verily in the creation of the heavens and the earth, and the alternation of the night and the day, there are signs (of Allah's greatness) for people of understanding.
(Surat Ali Imran: 190)