Why in 1493,would this discovery have been big news?

The discovery of America was great news because the Europeans found a great source of wealth, land and raw materials, beginning the most important colonizing expansion of the History of Humanity.

On October 12th in 1492 Christopher Columbus arrived to the coasts of a continent unknown until the moment for the Europeans, later denominated the America.

After having stayed a week in Portugal, Columbus returned to Spain and was received with high honors in Barcelona by the kings Isabel de Castilla and Fernando de Aragón, who had sponsored his trip in search of a new route to the East Indies to bring from there spices like ginger, black pepper and cloves.

Columbus and his remaining crew came home to a hero's welcome when they returned to Spain. He showed off what he had brought back from his voyage to the monarchs, including a few small samples of gold, pearls, gold jewelry stolen from natives, a few natives he had kidnapped, flowers, and a hammock. He gave the monarchs a few of the gold nuggets, gold jewelry, and pearls, as well as the previously unknown tobacco plant, the pineapple fruit, the turkey, and the hammock.

The news spread rapidly throughout Europe and signified the beginning of a new era of prosperity, territorial expansion and political and economic dominance of the European powers.

This new era brought a boom in international trade and cultural exchange, as well as the colonization of vast territories in the rest of the world.

For the Native Americans it was not considered good news because the beginning of prosperity in Europe brought as a counterpart the destruction of most of the civilizations of the American continent.