June 9, 2021 updates Posted on June 9, 2021 by Doug Loss Geochemistry and Cosmochemistry of potassium stable isotopes https://www.sciencedirect.com/science/article/abs/pii/S0009281921000489 The similarity of the interstellar comet 2I/Borisov to solar system comets from high resolution optical spectroscopy https://arxiv.org/abs/2106.04431 ET Probes: Looking Here as Well as There https://arxiv.org/abs/1609.04635