Could The Interstellar Object ‘Oumuamua Be A Solar Thermal Propulsion Vehicle
T. F. Sheerin, A. Loebb. (2021), JBIS, 74, pp.427-432
The first interstellar object, ‘Oumuamua, featured extreme geometry, excited rotation, and comet-like acceleration without detectable outgassing. Recent natural explanations contemplate objects that have never been observed before, including hydrogen and nitrogen icebergs, but these explanations are unlikely. Thus far, only a solar sail has been proposed as an alternative hypothesis, but there are other possibilities. This study investigates whether ‘Oumuamua could have been a solar thermal propulsion vehicle. Given the constraints obtained by the Spitzer Space Telescope on infrared radiation emitted by ‘Oumuamua, upper limits are derived for size and temperature of a notional exhaust hot spot, constraining its diameter to be smaller than one meter for temperatures above 800 K. These results may inform observational capability needs for future interstellar object transit events.