Starship Asterisk*

The first detection of an interstellar asteroid/comet-like object visiting the Solar system two years ago has sparked ideas about the possibility of interstellar travel. New research from the Technion–Israel Institute of Technology suggests that such objects also raise far reaching implications about the origins of planets across the galaxy, and possibly even the initial formation of the Solar system itself.

The asteroid/comet-like object named “’Oumuamua” confirmed decades-old scientific expectations that suggested that the interstellar medium is full of loose chunks of rock flying around. Such debris were thought to be ejected from planetary systems in the aftermath of planet formation, when large planets formed and kicked out some of the leftover minor-planets and planetesimals still lying around. From time to time, some fraction of these ejected rocks can still encounter foreign stars. In fortunate instances, this phenomenon can be observed as it swooshes through the Solar system.

The Technion researchers, Evgeni Grishin, Hagai Perets and Yael Avni wondered what would have happened if these ‘Oumuamua-like interstellar rocks were flying around 4.5 billion years ago, when our star was young and wild, and a gaseous disk was present instead of our planetary system. Their findings could be critical to answering some of the biggest puzzles regarding planet formation and the origin of planets in the Solar system. ...

• Monthly Notices of the RAS 487(3):3324 (Aug 2019) DOI: 10.1093/mnras/stz1505
• arXiv.org > astro-ph > arXiv:1804.09716 > 25 Apr 2018 (v1), 03 Mar 2019 (v4)