Planetary Science Institute Senior Scientist Thomas Prettyman was honored for his work on NASA’s Dawn mission that explored the asteroid Vesta and the dwarf planet Ceres.

The NASA Exceptional Scientific Achievement Medal was presented Sept. 6 to Prettyman “For exceptional scientific return and major discoveries that resulted at Vesta and Ceres from the successful Gamma Ray and Neutron Detector Investigation on Dawn,” said NASA’s award citation.

NASA says, “This award is given for individual efforts that have resulted in a key scientific discovery or resulted in contribution(s) of fundamental importance in this field or significantly enhanced understanding of the field.”

Prettyman is the principal investigator for the GRaND instrument, which measured the chemical composition of the surfaces of Vesta and Ceres using a combination of gamma ray and neutron spectroscopy. GRaND was developed at the Los Alamos National Laboratory and is managed by the Planetary Science Institute.

Visit for a photo of Prettyman receiving the medal.

Thomas Prettyman
Senior Scientist

Mark V. Sykes