Aliens "having existed/existing" is a vastly, utterly different question from whether they've "visited planet Earth". Yes, "aliens" have most certainly existed, at various times, elsewhere in the universe. The laws of physics obviously allow for intelligent life to evolve, therefore if it happened on our one planet, it will also have done so elsewhere.
I could imagine some small chance that a "ship" might someday arrive, but it won't contain living beings. Simply put, everywhere else is too far away, and the timing of their civilization would have to perfectly coincide with ours, such that they arrive in the impossibly slim sliver of geological time when we're here, looking for them. The same laws of physics will mean that any "aliens" will have finite lifespans, and those will not be the many thousands of years it would take to travel to Earth from, like, even the closest star to our own Sun, Proxima Centauri, which is 24,900,000,000,000 miles away.
No idea what you think has been "observed in recent years" 
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