A LASP-led and University of Colorado Boulder student-built instrument riding on NASA’s New Horizons spacecraft found only a handful of dust grains, the building blocks of planets, when it whipped by Pluto at 31,000 miles per hour last July.
Data downloaded and analyzed by the New Horizons team indicated the space environment around Pluto and its moons contained only about six dust particles per cubic mile, said LASP planetary scientist and CU-Boulder Professor Fran Bagenal, who leads the New Horizons Particles and Plasma Team.
“The bottom line is that space is mostly empty,” said Bagenal. “Any debris created when Pluto’s moons were captured or created during impacts has long since been removed by planetary processes.”
When NASA’s napping New Horizon’s spacecraft awakens later this week in preparation for its July 2015 encounter with Pluto, a University of Colorado Boulder student instrument onboard already will have been up for years.
The instrument, the Student Dust Counter (SDC), was designed and built to detect dust both on the interplanetary journey to Pluto and beyond, said CU-Boulder physics Professor and LASP research scientist Mihaly Horanyi, principal investigator on the effort. The SDC has been on for most of the mission—even as the other instruments primarily napped—measuring dust grains that are the building blocks of the solar system’s planets, he said.
Using data from the NASA New Horizons mission to Pluto, LASP scientists have made new measurements of interplanetary dust density. The data, collected from the CU-Boulder student-built Student Dust Counter (SDC) and the meteoroid detector on the Pioneer 10 spacecraft, represent measurements of the micro-sized dust grains from the Earth out to the present position of the SDC, at approximately 20 Astronomical Units (AU). One AU is equal to the average distance from the Sun to the Earth, or approximately 93 million miles (149.5 million km).