ESA stated this morning that the fireball seen over Portugal last night was a piece of a comet, not a meteor. Implying that it was composed mainly of ice, not rocky material?
"We estimate that it flew over Spain and Portugal travelling at ~45 km/s before burning up over the Atlantic Ocean at an altitude of ~60 km.
The likelihood of any meteorites being found is very low."
https://fosstodon.org/@esaoperations@bird.makeup/112467315956871360