One of tycho brahe's major contributions to astronomy was to prove that A comet was outside of Earths atmosphere.
One of tycho brahe's major contributions to astronomy was to prove that A Supernova was much farther away than the planets.
These are his two contributions
Trade across the Sahara became possible and it impacted West African empires by influencing them on a cultural level. The peak of Saharan trade <span>extended from the 8th century until the early 17th century.</span>