Brain Food: Studying Pluto's Ice
Pluto has a surface of nitrogen and methane ice. Scientists know this from telescope observations. But, when the New Horizons spacecraft flies by the dwarf planet in July, they hope to know far more about its icy composition. Flagstaff astronomer Stephen Tegler will be analyzing the data.
"Visiting a new world for the first time doesn't happen often," Tegler says. He heads up Northern Arizona University's Physics and Astronomy Department, and runs an ice lab on campus. NASA has asked Tegler to grow different methane nitrogen ices so that scientists can compare and interpret the data that comes back from the spacecraft. "We have the fingerprints of Pluto's ice and now we have this whole library of fingerprints of ices in our lab," Tegler says. "What we try to do is match the fingerprints from the Pluto spectra and from the spectra in the lab, and once you get a match, you can start to infer things like what's the phase of the ice, the temperature, the composition, to really get into the physical properties of the ice."
Tegler is hoping the New Horizons mission will also help scientists understand where the methane on Pluto's surface comes from. "The solar photons, the solar environment radiation should actually break the methane apart, and so it's got to be coming from someplace. It should be gone if it's not being replenished," Tegler says. "Is it coming from the interior? I'd like to know how active is the surface. Are there geysers there? Is there actually an active surface? An active world?"
Tegler says the combination of New Horizons images and NAU's ice samples will provide the most complete depiction yet of the distant and mysterious Pluto.