Question: a planet is furthest from the sun in its elliptical orbit when it is at
[{'answer': 'aphelion', 'provenance': [{'wikipedia_id': '88213', 'title': 'Apsis', 'start_paragraph_id': 1, 'start_character': 526, 'end_paragraph_id': 1, 'end_character': 534, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]