Because the way the headline is formulated, the A.I. is helping the planet orbit that distant star, though arguably the comma saves it.

I don't really want to write a grammar essay, but when you have two verbs in a sentence (orbiting, found) you should avoid splitting the dependent clauses (orbiting a distant start, found with AI help). Otherwise confusion may arise over which dependent clause belongs to which verb.

Sentences are clearest when written in the active rather than passive voice, and this is especially true in headlines. 'Scientists use AI to find new planet' is far better than 'A planet is found with help from AI'.

The Elements of Style is by far the best good to good clear writing in the English language. http://www.jlakes.org/ch/web/The-elements-of-style.pdf

No, that's not a valid construction in English. But this points to an interesting distinction between different language families that is useful to know about and aids mutual comprehension: https://en.wikipedia.org/wiki/Subject%E2%80%93verb%E2%80%93o...

The AI felt Neptune is better off elsewhere, so it moved the planet to an orbit around a distant star.

An 8th planet is found orbiting a distant star, with AIs, help?