Learn Russian: У этого феномена есть интересный аспект. - This phenomenon has an interesting aspect.

While we often drop есть when describing abstract, permanent characteristics (like У него хорошая память - He has a good memory), we keep it when emphasizing the actual existence or presence of something. Here, the sentence is declaring that an interesting aspect exists within this phenomenon, rather than just describing a permanent trait of the phenomenon itself.

Does the word феномен behave exactly like 'phenomenon' in English?

Mostly yes, but there is a tricky pronunciation rule to remember. When referring to a scientific or natural phenomenon, the stress is on the second syllable: фено́мен (which gives us the Genitive фено́мена here). However, if you are calling a person a prodigy or a rare talent, the stress shifts to the last syllable: феноме́н.

Since our current lesson is about представлять собой (to represent / to be), how would we use it to say 'This phenomenon IS an interesting aspect'?

You would say: Этот феномен представляет собой интересный аспект. The phrase представлять собой requires the Accusative case, but because аспект is an inanimate masculine noun, its Accusative form looks exactly identical to the Nominative case you see in the original sentence.

Could we use a formal definition verb like являться to make this sentence sound more academic?