NASA's Mission to Pluto and the Kuiper Belt
December 23, 2014
As the time for New Horizons Pluto system encounter approaches, I often think about the fact that the first time we've taken a close-up look at an object in the solar system, our understanding of that object immediately leaps forward. From volcanoes on Jupiter's moon Io, to hydrocarbon lakes on Saturn's moon Titan, to nitrogen geysers on Neptune's moon Triton, and innumerable other examples, we've seen remarkable things that have taught us much about what goes on in our sun's neighborhood.
The power of Ralph: The Linear Etalon Imaging Spectral Array (LEISA) – the half of the Ralph instrument that is able to "see" in infrared wavelengths – watched clouds of ammonia ice evolve over five Jupiter days (about 40 Earth hours) during New Horizons' flight past the giant planet in 2007.
Next year, New Horizons will be taking the first high-resolution views of the Pluto system, which represents an unexplored class of solar system bodies – small planets in the Kuiper Belt. While we have some idea of what we expect to see, I can't help but think that history will repeat itself, and we'll find ourselves astounded by something new, something we had never expected to see. And for me, as the instrument scientist for the Ralph color imager and infrared (composition mapping) spectrometer on New Horizons, the high likelihood that at least part of that "something new" will be recognized in data returned by that instrument is beyond exciting.
Not only will Ralph allow us to "see" things as if we ourselves were there, its infrared spectra will allow us to tell what specific molecules are on the surfaces of Pluto and its moons, how they are distributed, and what their environments are like. We've already seen how capable Ralph is from infrared and visible images taken of Jupiter in 2007 during the gravity assist maneuver that sped New Horizons to Pluto. The idea that planetary science will soon have that information for the Pluto system too is just remarkable!
Dennis Reuter, a New Horizons co-investigator from NASA Goddard Space Flight Center in Greenbelt, Md., is the instrument scientist for Ralph, the New Horizons color imager and infrared spectrometer.