During its 2010 "Annual Checkout" in July, New Horizons turned its highest-resolution camera, LORRI, toward the Neptune system. As far as New Horizons is from Earth (more than 17 astronomical units), it was actually even farther from Neptune when it captured this photo (23 A.U.) Even at this enormous distance, New Horizons was able to separate the light of Neptune's largest moon Triton from the light of the planet, which was 100 times brighter.

NASA / JHUAPL / SwRI