Assertion: mercury's atmosphere | /r/HasProperty | significant
Facets:
Source sentences:
text: Since it has no significant atmosphere to stop impacts, the planet is pockmarked with craters.
text: Since it has no significant atmosphere to stop impacts, the planet is pockmarked with craters.
text: However, this theory was abandoned when the effect was also observed during the Mercury transit in 1999 because Mercury has no significant atmosphere.