Tesla Inc. Chief Executive Officer Elon Musk and Alibaba Group Holding Ltd. Chairman Jack Ma, two of the leading luminaries in the technology world, sparred against each other on Thursday on subjects ranging from the dangers of artificial intelligence, the need to explore Mars and the future of education.

Held at the World Artificial Intelligence Conference in Shanghai, the rare debate between China's richest man and one of America's more controversial billionaires began with thoughts on AI -- Ma is betting humans will prevail over machines, while Musk fears doomsday is coming -- but the conversation, which went viral on social media, soon transgressed into areas such as Mars exploration and aliens.

Read more: The Time a Jet-Lagged Musk Made Alibaba's Jack Ma Sound Grounded

Below are some of the more memorable exchanges, which have been edited lightly for clarity.

On Artificial Intelligence

Musk: People underestimate the capability of AI. They sort of think like it's a smart human. (But it's going to be) much smarter than the smartest human you will ever know.

Ma: I never in my life say human beings will be controlled by machines, it's impossible...Human beings can never create another thing that is smarter than human beings.

Musk: I very much disagree with that. The biggest mistake I see people making is to assume they're smart.

Ma: My view is that computers might be more clever, human beings are much smarter.

Musk: Yeah, definitely not.