。
Planets rotate around the sun.
Literal
Planet [topic-は] sun [possessive-の] surroundings [object-を] rotate.
A simple astronomy fact. 惑星 (わくせい) 'planet'. 太陽 (たいよう) 'sun'. 周囲 (しゅうい) 'surroundings, area around'. 回転する ('to rotate, revolve') can mean both 'rotate on own axis' and 'revolve around'. Here the meaning is 'revolve around'. The object particle を marks the path of movement.