This week's heresy is actual not a heresy at all, but an interesting piece of church history nonetheless.
Heliocentrism is a Renaissance-era “heresy” that teaches (correctly) that the sun is the center of the solar system. It was deemed heretical because it was thought to contradict several Bible passages. Nicholas Copernicus was the first to write about this, but Galileo Galilei was perhaps most famous for his confrontations with the Church over this. It was never officially declared a heresy, although books on the subject were put on the index of forbidden books. In 1992, Pope John Paul II issued an apology on behalf of the Vatican over the “Galileo affair”.