Aliens reaching Earth?

If aliens exist, how intelligent and powerful do they have to be to reach Earth? Could they come here for any other reason than to colonize us?

https://www.quora.com/If-aliens-exist-how-intelligent-and-powerful-do-they-have-to-be-to-reach-Earth-Could-they-come-here-for-any-other-reason-than-to-colonize-us/answer/Jainil-Patel-16?ch=10&oid=278731359&share=a247ee5a&srid=2P28&target_type=answer

My Last FM Chart

http://www.lastchart.com.s3-website-us-east-1.amazonaws.com/#lfm=RogerRamos1993