Space and High-Irradiance Near-Sun Simulator (SHINeS)

We have developed a high-irradiance space simulator,  SHINeS which can be used to replicate the thermal environment in the immediate neighborhood of the Sun down to a heliocentric distance of about 0.06 au.

Our motivation for building this experimental system was to study the effect of intense solar radiation on the surfaces of asteroids when their perihelion distances become smaller than the semi-major axis of the orbit of Mercury.   The most recent population models (Granvik et al. 2016, 2017,2018) for NEAs predict far more objects with small perihelion distances than those observed. The discrepancy of a factor of almost 9 disappears when a hypothesized mechanism of total disruption of these objects is introduced in the model, with an average disruption distance of 0.076 au.

Previous experimental studies on the processes on asteroid surfaces include the thermal crack growth experiments of Delbo et al. 2014, optical mining technology demonstrations by Dreyer et al. 2016, and the volatility of Sodium as the primary mechanism for Phaethon’s activity by Masiero et al.2021.

SHINeS was developed to directly mimic the conditions an asteroid’s surface experiences at various heliocentric distance in terms of Solar irradiance, rather than trying to match the predicted temperature in a more conventional heating experiment. Thus, SHINeS consists of a powerful Solar simulator and a large vacuum chamber, complemented by an assortment of measuring and monitoring devices to closely record the processes on the surface and interiors of illuminated samples.

Our preliminary studies are focused on samples of CI asteroid simulants to find the correlation between the rate of disruption and the heliocentric distance of an object.