Assertion: mercury | /r/HasProperty | bombarded
Facets:
value: during a possibly separate subsequent event
type: TEMPORAL
value: by asteroids
type: OTHER
value: by comets
type: OTHER
Source sentences:
text: It is believed that Mercury was heavy bombarded by comets and asteroids during and shortly after its formation 4.6 billion years ago, as well as during a possibly separate subsequent event called the Late Heavy Bombardment that ended 3.8 billion years ago.