Meteoroids cannot create islands. A meteoroid the size of the island shown, crashing into the Earth, would have caused an extinction-level event and left a large crater on the ocean floor or even stripped away/liquefied the Earth's whole crust.
At one point, Tintin observes the titular asteroid through a big telescope. It looks as though there was a giant spider on it but Tintin finds out that the spider was just crawling across the telescope's front lens. In reality, objects on the front lens are so far out of focus as to be invisible, causing at most some extra blur.
However, as it turns out, this happens in a dream sequence where anything is possible.
It makes no sense that the meteorite should cause supernatural growth in all living organisms on the island, including an apple tree, but not in Tintin and Snowy.