Possible Clues:

• For viewing this heavenly body, withdraw to compose state of mind
• Write about melody part of Holst's famed suite
• Planet circled by Triton
• Writer returns to melody from deity
• Poseidon
• Its largest moon is Triton
• Planet discovered in 1846
• World record once in qualification, but you win bronze, finally
• Eighth of eight
• Write up melody for movement from 'The Planets'