He missed Fajr prayer and found the congregation offering the eclipse prayer

If a man comes late for Fajr prayer, can he join the imam whilst he is
offering the eclipse prayer?.
Praise be to Allaah.
If he knows that he is offering the eclipse prayer, then he should not
join him, because of the difference in nature between the two prayers.
Although the eclipse prayer is two rak'ahs, each rak'ah includes two
bowings, two standings and two recitations. So whoever does not
realize that the imam is offering the eclipse prayers and join the
imam with the intention of praying Fajr should form the intention of
praying separately from the imam when he realizes that the imam is
offering the eclipse prayer. Then he should complete his prayer as
Fajr and then if he wants he may join the imam for whatever is left of
the eclipse prayer.
And Allaah is the Source ofstrength.