This seems to be a hypothetical question.
As per many Sahih Hadiths, humans will be still alive when the Last Hour arrives. They are also stated to be the worst of human kind fornicating like donkeys in broad daylight.
Nawwas bin Sam'an Al-Kilabi said: "The Messenger of Allah (ﷺ)
mentioned Dajjal, one morning, as something despised but also
alarming, until we thought that he was in the stand of date-palm
trees. When we came to the Messenger of Allah (ﷺ) in the evening, he
saw that (fear) in us, and said: 'What is the matter with you?' We
said: 'O Messenger of Allah, you mentioned Dajjal this morning, and
you spoke of him as something despised but also alarming, until we
thought that he was in the stand of date-palm trees.' He said: 'There
are things that I fear more for you than the Dajjal. If he appears
while I am among you, I will contend with him on your behalf, and if
he appears when I am not among you, then each man must fend for
himself, and Allah will take care of every Muslim on my behalf. He
(Dajjal) will be a young man with curly hair and a protuberant eye; I
liken him to 'Abdul-'Uzza bin Qatan. Whoever among you sees him, let
him recite the first Verses of Surat Al-Kahf over him. He will emerge
from Khallah, between Sham and Iraq, and will wreak havoc right and
left. O slaves of Allah, remain steadfast.' We said: 'O Messenger of
Allah, how long will he stay on earth?' He said: 'Forty days, one day
like a year, one day like a month, one day like a week, and the rest
of his days like your days.' We said: 'O Messenger of Allah, on that
day which is like a year, will the prayers of one day suffice us?' He
said: 'Make an estimate of time (and then observe prayer).' We said:
'How fast will he move through the earth?' He said: 'Like a rain cloud
driving by the wind.' He said: 'He will come to some people and call
them, and they will respond and believe in him. Then he will command
the sky to rain and it will rain, and he will command the earth to
produce vegetation and it will do so, and their flocks will come back
in the evening with their humps taller, their udders fuller and their
flanks fatter than they have ever been. Then he will come to some
(other) people and call them, and they will reject him, so he will
turn away from them and they will suffer drought and be left with
nothing. Then he will pass through the wasteland and will say: "Bring
forth your treasures," then go away, and its treasures will follow him
like a swarm of bees. Then he will call a man brimming with youth and
will strike him with a sword and cut him in two. He will put the two
pieces as far apart as the distance between an archer and his target.
Then he will call him and he will come with his face shining,
laughing. While they are like that, Allah will send 'Eisa bin Maryam,
who will come down at the white minaret in the east of Damascus,
wearing two Mahrud[garment dyed with Wars and then Saffron], resting
his hands on the wings of two angels. When he lowers his head, beads
of perspiration will fall from it. Every disbeliever who smells the
fragrance of his breath will die, and his breath will reach as far as
his eye can see. Then he will set out and catch up with him (the
Dajjal) at the gate of Ludd, and will kill him. Then the Prophet of
Allah 'Eisa will come to some people whom Allah has protected, and he
will wipe their faces and tell them of their status in Paradise. While
they are like that, Allah will reveal to him: "O 'Eisa, I have brought
forth some of My slaves whom no one will be able to kill, so take My
slaves to Tur in safety." Then Gog and Magog will emerge and they
will, as Allah describes, "swoop down from every mound."[21:96] The
first of them will pass by lake Tiberias and drink from it, then the
last of them will pass by it and will say: "There was water here
once." The Prophet of Allah, 'Eisa and his companions will be besieged
there until the head of an ox would be dearer to any one of them than
one hundred Dinar are to any one of you today. Then, the Prophet of
Allah, 'Eisa and his companions will supplicate Allah. Then Allah will
send a worm in their necks and the next morning they will all die as
one. The Prophet of Allah 'Eisa and his companions will come down and
they will not find even the space of a hand span that is free of their
stink, stench and blood. They will pray to Allah, and He will send
birds with necks like the necks of Bactrian camels, which will pick
them up and throw them wherever Allah wills. Then Allah will send rain
which will not leave any house of clay or hair, and it will wash the
earth until it leaves it like a mirror (or a smooth rock). Then it
will be said to the earth: "Bring forth your fruits and bring back
your blessing." On that day a group of people will eat from a (single)
pomegranate and it will suffice them, and they will seek shelter
beneath its skin. Allah will bless a milch- camel so that it will be
sufficient for a large number of people, and a milch-cow will be
sufficient for a whole tribe and a milch-ewe will be sufficient for a
whole clan. While they are like that, Allah will send a pleasant wind
which will seize them beneath their armpits and will take the soul of
every Muslim, leaving the rest of the people fornicating like donkeys,
and upon them will come the Hour.'"
Sunan Ibn Majah 4075
Infact there some ulema who use this same reasoning to say that human race will not move to other planets and are confined to Earth. It is also important to remember that Iblees not only tries to make humankind go astray but does so too among the Jinnkind. We have believers & disbelievers among both creations whom Allah will judge as per His Decree.
