A string of 13 dwarf galaxies in orbit around the massive galaxy Andromeda –remnants of the population of primordial structures that coalesced to form giant galaxies like the Milky Way–are spread across a flat plane more than one million light years wide and only 30,000 light years thick –a distance so vast that they have yet to complete a single orbit. The 2016 discovery suggests that conventional ideas regarding the formation of galaxies are missing something fundamental.
Editor, Jackie Faherty, astrophysicist, Senior Scientist with AMNH. Jackie was formerly a NASA Hubble Fellow at the Carnegie Institution for Science. Aside from a love of scientific research, she is a passionate educator and can often be found giving public lectures in the Hayden Planetarium. Her research team has won multiple grants from NASA, NSF, and the Heising Simons foundation to support projects focused on characterising planet-like objects. She has also co-founded the popular citizen science project entitled Backyard Worlds: Planet 9 which invites the general public to help scan the solar neighbourhood for previously missed cold worlds. A Google Scholar, Faherty has over 100 peer reviewed articles in astrophysical journals and has been an invited speaker at universities and conferences across the globe. Jackie received the 2020 Vera Rubin Early Career Prize from the American Astronomical Society, an award that recognises scientists who have made an impact in the field of dynamical astronomy and the 2021 Robert H Goddard Award for science accomplishments.
“It was shocking to realize that the Milky Way had a large sibling, and we never knew about it,” said Eric Bell, University of Michigan professor of astronomy in 2018 about his discovery that the Andromeda galaxy (also named M31), our closest large galactic neighbor, shredded and cannibalized a massive galaxy two billion years ago.