Red Friday was a conflict on Mars between the Terra Firma movement and the Terran Federation government.
Following the Strekkelan War, some refugees from Strekkelan destroyed worlds were relocated to several colonies in Terran Federation space. When some refugees came to Mars, members of Terra Firma on the planet stormed several refugee ships, killing a few aliens on the ships. This led to Terr a Firma being declared a threat and near-decimation of the movement within a year.
The resulting conflict led to Terra Firma turning to street preaching.