Prof.Heidi Jo Newberg explains how the MilkyWay@home volunteer supercomputer was used to determine the shape and dark matter content of the ultrafaint dwarf galaxy that fell into the Milky Way three billion years ago and was ripped apart to form the Orphan-Chenab Stream (OCS).The measured dark matter mass is ten times less than that of dwarf galaxies observed today.This could mean that ultrafai...