Why do astronomers from geocentric model to the heliocentric model?

Ptolemy develops a geocentric model that has the planets moving around the Earth. However, in order to account for retrograde motion, he put the planets on circles that move in circles. * Copernicus suggests a heliocentric model. His model has the planets moving around the Sun in circular orbits.

B. to study the spatial patterning of forests and forests fires and plan for better use of fire fighting resources in the u.s.

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen