Giordano Bruno is executed for heresy by being burned at stake. Giordano Bruno was a philosopher and Dominican monk who supported the Copernican model of the solar system and advocated and extreme form of pantheism.
In cosmology, Giordano Bruno believed not only that the earth orbits the sun, but also that the sun is a star like the others we see a night. Moreover, those stars have planets orbiting them - planets which may have life on them. He also believed the universe is infinite in size, reflecting the infinite nature of God.
According to Bruno, God is the single unifying substance from which everything in the universe is ultimately derived. Other views of Bruno were apparently more heretical, resulting in objections and criticism from church authorities.