Input (grade 10): One of Phaethon's most remarkable distinctions is that it approaches the Sun closer than any other numbered asteroid: its perihelion is only 0.140 AU - less than half Mercury's perihelion distance.
Output (grade 8): Phaethon approaches the Sun closer than any other numbered asteroid. Its perihelion (closest approach to the Sun) is only 0.140 AU - less than half Mercury's perihelion distance.