LOW-TEMPERATURE SPECIFIC HEAT CAPACITY AND LINEAR THERMAL EXPANSION OF MATERIAL FROM ASTEROID 101955 BENNU

OSIRIS-REx returned a sample from asteroid (101955) Bennu on 24 September 2023. Bennu was chosen as the target of study because of its primitive origins dating to the birth of our Solar System [1]. Bennu has a low-albedo surface and is classified as a B-type (spectrally blue) asteroid, a sub-type of the carbonaceous (C-type) asteroids. Low temperature measurement of specific heat capacity (3– 250 K), a key parameter in determining thermal inertia, allows a thermodynamic profile of this asteroid material for comparison with CM and CI meteorites and other asteroids, helping us to understand the chemical evolution of the early solar system. Thermal expansion measurements (12–300 K) provide data for thermal fatigue modeling and understanding the evolution of asteroid surface material [2, 3]. Such measurements inform the primary hypothesis of the OSIRIS-REx mission of how the surface materials of Bennu have been modified by exposure to space.