Although there's no details visible in the image below, it's still a pretty impressive feat. During an annual checkout of its instruments, New Horizons turned back to snap a photo of Jupiter, which it passed by more than three years ago. The planet is now 16.3 astronomical units away -- more than 2.4 billion kilometers -- and New Horizons is seeing light that left Jupiter more than two hours previously. Even more impressive, the Sun was only 17 degrees away from Jupiter in New Horizons' sky, glowing away at a whopping 460 million times Jupiter's apparent brightness. That, in fact, was the real reason for this photo; they wanted to see how the LORRI camera would perform under such viewing geometry, which will be similar to the "lookback" images they'll be snapping as they recede from their Pluto encounter.
NASA / JHUAPL / SwRI
New Horizons looks at Jupiter from more than 16 AU away
In a test designed to study its camera's ability to image things close (in angular terms) to the Sun, New Horizons turned back to look at Jupiter again on June 24, 2010, more than three years after its gravity assist flyby. New Horizons was 16.3 astronomical units (more than 2.4 billion kilometers) from Jupiter at the time, meaning that the light from Jupiter took approximately 136 minutes to reach the spacecraft.