Question: when did the challenger space shuttle blow up
[{'answer': 'On January 28 , 1986', 'provenance': [{'wikipedia_id': '403717', 'title': 'Space Shuttle Challenger disaster', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '403717', 'title': 'Space Shuttle Challenger disaster', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1061, 'bleu_score': 0.8372010573577561, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12811479092516594317}, 'section': 'Section::::Abstract.'}]}]