Free Astronomy Magazine March-April 2019

7 MARCH-APRIL 2019 ASTROBIOLOGY trial life on potentially habitable extrasolar planets. One of these is the Genesis Project, promoted since 2016 by Claudius Gros of the Institut für Theoretische Physik of the Goethe-Universität in Frankfurt. The idea is based on optimistic assumptions but far from the abstract: it considers three areas of research that have progressed in recent years to the point of allowing a serious as- sessment of the feasibility of interstellar travel, even with a biological load. The first area of research is in the great num- bers of extrasolar planets and the unveiling of the great variety of existing worlds, a per- centage of which may not be able to gener- ate their own biosphere, but may be able to host one introduced from outside. The second area concerns the possibility of significantly shortening interstellar travel times by accelerating miniaturized, and therefore very light, probes at speeds of tens of thousands of km/s using arrays of powerful laser beams, as foreseen by Star- shot Breakthrough Systems. The third area upon which the Genesis Proj- ect relies concerns recent progress in the synthesis of microbes that allows us to con- sider the possibility of using a biological mini-laboratory to synthesize single-cell or- ganisms, starting from their constitutive subcellular elements and tailored to the tar- get planets. In the case of relatively short travels, it could directly send dormant spores, which are then revitalized once the destination is reached. It is likely that, by the end of this century, a project similar to the one proposed by Gros can be started. It is, therefore, licit to ask ourselves today what ethical and prac- tical issues must be addressed to lead to its realization. As you can easily imagine, time is the deter- mining factor for defining the purposes of interstellar travel. The form of propulsion known as “directed energy launching sys- O n the right and on the bottom, possible designs of the structures needed to brake the Genesis spacecrafts near their destinations. [Steve Bowers]