How can we determine the interior structure of asteroids with laser vibrometry?
Asteroids hold insightful information about solar system formation, and could provide valuable resources for future human space exploration. Traditional seismological techniques require measurement of the surface motion after impacting the body, commonly via numerous seismometers physically coupled to the surface. However this is infeasible in a planetary setting due to the complexity of spaceflight missions requiring landing on bodies characterized by microgravity. We are developing a new instrument based on the laser Doppler vibrometer (LDV) concept to perform seismological observations remotely from a satellite orbiting the body of interest. This approach allows us to design an instrument capable of measuring ground motion at numerous points of interest after each impact source with very high precision. This new seismology technique will likely lead to new discoveries about asteroid formation, thus aiding resource exploration and mitigation of space hazards.
This research is done in conjunction with the interdisciplinary team in Space Resources.
Laser Doppler Vibrometry
Top: Prototype. Bottom: Measurement of surface motion from prototype LDV with artificial surface set to move at 1Hz with 1um amplitude. The instrument is very capable of measuring this motion, as well as the natural resonance of the artificial surface at 22Hz with 0.5um amplitude.