Sequence of tenses for facts irrelevant of the moment of speech

Let's consider two sentences:

(1) I suggested that the word zeitgeist was of German origin.
(2) The lecturer said the Pluto's orbital period is more than 200 years.

In both cases, the facts are always valid and irrelevant of the moment of speech and context. I've heard sequence of tenses is not required in such cases. Are past and present tenses interchangeable in both of them? Would it be correct to say:

(1) I suggested that the word zeitgeist is of German origin.
(2) The lecturer said the Pluto's orbital period was more than 200 years.