The authors would like to thank the referee, Prof. Todd Hillwig, for his extremely insightful report which greatly improved the paper. The authors are also grateful to Prof. Bruce Balick for helping to obtain the APO data, and to Prof. Z. Eker for providing the corrected form of the mass-radius relationship. JM acknowledges the support of the ERASMUS+ programme in the form of a traineeship grant. DJ, JGR, PRG and RLMC acknowledge support from the State Research Agency (AEI) of the Spanish Ministry of Science, Innovation and Universities (MCIU) and the European Regional Development Fund (FEDER) under grant AYA2017-83383-P. DJ and JGR also acknowledge support under grant P/308614 financed by funds transferred from the Spanish Ministry of Science, Innovation and Universities, charged to the General State Budgets and with funds transferred from the General Budgets of the Autonomous Community of the Canary Islands by the Ministry of Economy, Industry, Trade and Knowledge. MSG acknowledges support from the Spanish Ministry of Science, Innovation, and Universities under grant AYA2016-78994-P. PS thanks the Polish National Center for Science (NCN) for support through grant 2015/18/A/ST9/00578. The authors thankfully acknowledge the technical expertise and assistance provided by the Spanish Supercomputing Network (Red Española de Supercomputación), as well as the computer resources used: the LaPalma Supercomputer, located at the Instituto de Astrofísica de Canarias. Based on observations made with the Isaac Newton Telescope and the William Herschel telescope both operated by the Isaac Newton Group of Telescopes, with the Mercator Telescope operated by the Flemish community, and with the Liverpool Telescope operated by Liverpool John Moores University with financial support from the UK Science and Technology Facilities Council, all of which reside on the island of La Palma at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013, 2018).

Spontaneous deracemizations is a challenging, multidisciplinary subject in current chirality research. In the absence of any chiral inductors, an achiral substance or a racemic composition is driven into an enantioenriched or even homochiral state through a selective energy input, e.g., chemical potential, photoirradiation, mechanical grinding, ultrasound waves, thermal gradients, etc. The most prominent examples of such transformations are the Soai reaction and the Viedma deracemization. In this review, we track the most recent developments in this topic and recall that many other deracemizations have been reported for solutions from mesophases to conglomerate crystallizations. A compiled set of simply available achiral organic, inorganic, organometallic, and MOF compounds, yielding conglomerate crystals, should give the impetus to realize new experiments on spontaneous deracemizations. Taking into account thermodynamic constraints, modeling efforts have shown that structural features alone are not sufficient to describe spontaneous deracemizations. As a guideline of this review, particular attention is paid to the physicochemical origin and symmetry requirements of such processes.

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