Near Term Interstellar Missions: Finding and Reaching Interstellar Objects

摘要

Just as comets have provide much information about the formation and history of the solar system, interstellar comets have much to teach us about the formation of exoplanets and the history of the Galaxy. After finding two exovistors in as many years, it seems likely that more such objects will be found as surveys and instruments continue to improve. We show how kinematic associations with dynamical stellar streams can be used to relate a given ISO to its stellar origin, and that the two known Interstellar Objects (ISOs), 1I/'Oumuamua and 2I/Borisov, are associated with the relatively young Pleiades Stream and the older Wolf 630 stream, respectively. Much will undoubtedly be learned from the remote spectrographic study of cometary exovisitors such as 2I/Borisov, but our experience with solar system bodies shows that much more information can be obtained from direct in situ exploration. We briefly describe the proposed missions to the two known ISO, loitering missions to yet to be discovered ISO, and how spectral information can be determined through use of a hypervelocity impactor. Missions to ISOs will be not just interstellar missions, but galactic missions, and will provide a means to sample regions of the Milky Way that otherwise take millennia, even with light-speed interstellar travel.