Do I need parentheses or dashes in this sentence?

Question

Copernicus   as you might know.   decided that the earth travels around the sun.

Ms. Sue · Answer

You need commas after Copernicus and after know.

Reed · Answer

I would use commas to set off, "as you might know,"

Kelley · Answer

My on,y choices are dashes and parentheses.... Dashes show an abrupt break in thought Parentheses set off material loosely related.

Writeacher · Answer

Both Ms. Sue and Reed are correct. Only commas are needed in this sentence. There's a problem with your text and/or the question.