Planet is a very simple straightforward word (very useful when teaching astronomy for the first time)...That is perhaps the problem with all those discoveries.
The trick would be to keep it simple while being accurate.

Even the difference between french and english is tricky in this field:

Un astre (from the latin "Astrum") is a "celestial body" (not just a star) and such a simple word doesn't exist in english.

I'm expected to speak in front of an audience of EU employees next week and was asked to find a title for the conference: A la découverte des étoiles was proposed but we don't only see stars in the heavens, so I thought "A la découverte des astres" but "des astres" sounds so much like "désastre" our disaster....Back to square one for the fun;))))