Question: what is the snow on mars made of
[{'answer': 'water ice', 'provenance': [{'wikipedia_id': '28203358', 'title': 'Martian polar ice caps', 'start_paragraph_id': 2, 'start_character': 44, 'end_paragraph_id': 2, 'end_character': 53, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Frozen carbon dioxide', 'provenance': [{'wikipedia_id': '28203358', 'title': 'Martian polar ice caps', 'start_paragraph_id': 2, 'start_character': 55, 'end_paragraph_id': 2, 'end_character': 76, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'CO ice ( dry ice )'}, {'provenance': [{'wikipedia_id': '28203358', 'title': 'Martian polar ice caps', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 411, 'bleu_score': 0.664144242058842, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 286320642302516099}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '28203358', 'title': 'Martian polar ice caps', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 924, 'bleu_score': 0.97353963039443, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 286320642302516099}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '28203358', 'title': 'Martian polar ice caps', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 286320642302516099}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '28203358', 'title': 'Martian polar ice caps', 'section': 'Section::::Abstract.', 'start_paragraph_id': 2, 'end_paragraph_id': 2, 'meta': {'evidence_span': ['The caps at both poles consist primarily of water ice. Frozen carbon dioxide accumulates as a comparatively thin layer about one metre thick on the north cap in the northern winter, while the south cap has a permanent dry ice cover about 8\xa0m thick', 'The caps at both poles consist primarily of water ice. Frozen carbon dioxide accumulates as a comparatively thin layer about one metre thick on the north cap in the northern winter, while the south cap has a permanent dry ice cover about 8\xa0m thick. The northern polar cap has a diameter of about 1000\xa0km during the northern Mars summer, and contains about 1.6 million cubic km of ice, which if spread evenly on the cap would be 2\xa0km thick.', 'The caps at both poles consist primarily of water ice. Frozen carbon dioxide accumulates as a comparatively thin layer about one metre thick on the north cap in the northern winter,']}}]}, {'provenance': [{'wikipedia_id': '21025499', 'title': 'Martian soil', 'section': 'Section::::Observations.\n', 'start_paragraph_id': 22, 'end_paragraph_id': 22, 'meta': {'evidence_span': ['It is believed that large quantities of water and carbon dioxide ices remain frozen within the regolith in the equatorial parts of Mars and on its surface at higher latitudes', 'It is believed that large quantities of water and carbon dioxide ices remain frozen within the regolith in the equatorial parts of Mars and on its surface at higher latitudes.']}}]}]