Dancers, celebrities and science lectures kicked off the biggest show in the known universe Friday night as space tourist Guy Laliberté brought his crusade to conserve water down to Earth.

Laliberté spent months planning the event that some are dubbing Spacestock — a concert on five continents, with the Cirque du Soleil founder acting as the master of ceremonies from the International Space Station.

Guy Laliberté introduces the Moving Stars and Earth for Water show from the International Space Station, as seen on a screen at the Montreal performance Friday. (Paul Chiasson/Canadian Press)The billionaire circus impresario hopes his grandiose event, "Moving Stars and Earth for Water," will focus the world's attention on an important cause: water conservation.

"Water touched me and inspired me," Laliberté said from space.

"Water is a source of life. When I learned a few years back that a child dies every eight seconds because of contaminated water, I knew it was urgent to act."

The proceedings kicked off with a science lecture from former U.S. vice-president Al Gore and Canadian environmentalist David Suzuki, who recounted the threats to water on the planet.

"Perhaps it's time for us to pause and reflect," Suzuki said.

"Perhaps it's time for us to change."

The event took a more traditional Cirque du Soleil spin when it switched from the two segments with Gore and Suzuki to Laliberté's hometown of Montreal, where internationally acclaimed writer Yann Martel and Canadian astronaut Julie Payette told a story about an argument between the sun and the moon, with water caught in the middle.

That was capped with dancers in aboriginal garb and a rain shower on the stage.

In an email exchange with journalists Friday, Laliberté said watching the Earth from up above helped him appreciate the environment even more. He called his two-week trip to space a life-changing experience.

The high point of his visit came Friday night with the extravaganza in 14 cities, featuring U2, Shakira, Peter Gabriel and Gore.

"When you see the Earth from up here it gives you an entire other perspective. First of all, it's so emotional. It's like living art in front of your eyes," Laliberté said earlier as he fielded emailed questions from journalists.

"But what really strikes me is you see that thin layer of protection. As much as I look away in space, or around, what you see there is absolutely fantastic — and fragile."

The production costs for the multilingual show are estimated to be between $6 million and $10 million — which is on top of the $35 million US Laliberté paid to become Canada's first space tourist.