לְפָנָיו֙ רָ֣גְזָה אֶ֔רֶץ רָעֲשׁ֖וּ שָׁמָ֑יִם שֶׁ֤מֶשׁ וְיָרֵ֙חַ֙ קָדָ֔רוּ וְכוֹכָבִ֖ים אָסְפ֥וּ נָגְהָֽם׃
Before them the earth quaketh, The heavens tremble; The sun and the moon are become black, And the stars withdraw their shining.
Rashi on Joel
the heavens tremble—Because of the retribution coming upon Israel, they quake and tremble.