Why did explorers look for a northwest passage?

Answer 1

So they could find a quicker, safer, route to China to trade for spices and silk.
They wanted to find a shorter route to Asia to find spices/silks not made/found in their country quicker and cheaper, they also wanted a new route because the route would consist of less on-land travel which meant fewer landing taxes. They knew it would be possible because there was new theories being studied about the world,and new devices being made to help make traveling easier and quicker
The Northwest Passage was wanted to be found in order to find a pathway for trade with Asia.
Finding the Northwest Passage was important because people wanted to go to Asia for the silk, spices, slaves, and gold.
Goods from East Asia, such as silk and spices, were highly prized in Europe. However, traveling by land to the Far East was a long and perilous voyage.

So, sailors attempted to find a way to sail there. Columbus believed the world was round, and so he sailed west to get to Asia, although he miscalculated the incredible distance he would need to sail. When he discovered the Americas, people thought that he had found Asia, but the soon found out it wasn't Asia. Vasco da Gama came up with a different route, which circled around southern Africa and then crossed the Indian ocean, although it was treacherous.

But Europeans still thought that you could sail west to get to Asia, like Columbus had believed. They just thought that they would need to find a waterway through the Americas, which were blocking their path. They called it the Northwest Passage, but it didn't exist and thus was never discovered.
The Europeans wanted to find a shorter route to Asia.They wanted to find it because the fur trade business was a growing business.Christopher Columbus thought this would work.

Answer 2

To find an easier access to Asia trade routes.