HTML:
<div class="description">
Planet Nine was initially proposed to explain the clustering of orbits
Of Planet Nine's other effects, one was unexpected, the perpendicular orbits, and the other two were found after further analysis. Although other mechanisms have been offered for many of these peculiarities, the gravitational influence of Planet Nine is the only one that explains all four.
</div>

BeautifulSoup code:
description_box = soup.find('div', {'class':'description'})
description = description_box.get_text(separator=" ").strip()
print description