Is it possible that small exoplanet, which does not acquire magnetosphere, has an atmosphere? To my small understanding, the magnetosphere is necessary to have atmosphere because of solar winds which can destroy atmosphere (this happened on Mars right). And we are almost sure that planets exist outside of star systems. So hypothetically, is it possible for such planet to sustain atmosphere without functional magnetosphere outside of star system?

Thanks and please be sympathetic with me. I am no close to astronomy and english (unfortunately).