Assertion: mercury | /r/HasProperty | difficult planet
Facets:
value: with to see it
type: PURPOSE
Source sentences:
text: Owing to its proximity to the Sun, Mercury is a difficult planet to visit.
text: Owing to its proximity to the Sun, Mercury is a difficult planet to visit.
text: It is a difficult planet to observe because of its proximity to the star, with the only times to see it with the naked eye being right before dawn and right after sunset.