After traveling through the inner solar system for seven years, NASA's MESSENGER spacecraft reached Mercury in March 2011 and became the first ever mission to orbit this mysterious planet. Since then MESSENGER has been making measurements with its suite of scientific instruments including gamma-ray, neutron and x-ray spectrometers, magnetometer, laser altimeter, cameras and other instruments. This data is helping to resolve many of the questions and mysteries surrounding Mercury's formation and composition. One of those instruments, the gamma-ray spectrometer, faced a unique challenge on this mission. Although it offers superb resolution for identifying radioactive materials, it only does so at an operating temperature of -300oF or below. This is quite daunting considering that Mercury is the closest planet to the Sun and its surface can reach 800oF. Accomplishing this required innovative new designs to protect this instrument from the blistering heat and allow it to cool. This presentation discusses the MESSENGER mission with a focus on the gamma-ray spectrometer and the importance of gamma-ray science in helping to understand the planet. This talk also discusses the science and engineering that allowed for the spectrometer to work at cryogenic temperatures in one of the hottest places in the solar system.

MESSENGER image provided by NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Speaker Bios

Dr. Morgan Burks

Dr. Morgan Burks is a physicist at Lawrence Livermore National Laboratory and specializes in instrumentation for gamma-ray spectroscopy and gamma-ray imaging. He helped build the first instrument that could accurately image and locate gamma-ray sources with a 360o field of view. He also built the first high-resolution, portable, gamma-ray spectrometer that could fit in the palm of your hand. Morgan received his PhD in Applied Physics in 1998 from the University of Arkansas at Little Rock; however, his graduate years were spent at Lawrence Berkeley National Laboratory where he developed a novel type of readout for charged particle detectors.

Dan Burns

Earth and Space Science and AP Physics Teacher
Los Gatos High School

Dan Burns has been teaching Earth and Space Science and AP Physics at Los Gatos High School since 1992. He is the LGHS science department chair and past president of the Northern California/Nevada American Association of Physics Teachers. He has worked on curriculum development and teacher workshops for the SETI Institute, the USGS, NASA, AAPT, and San Jose State University. He has a BS in Aerospace Engineering from the University of Illinois. Prior to becoming a teacher Dan was a senior research specialist for the Lockheed Missiles and Space Company. Dan is an avid amateur astronomer and astrophotographer and has had several pictures published in astronomy magazines.