The dark side of the moon. An ancient celestial mystery that’s captured imaginations for millennia. Earth’s eternally distracted friend. And a bestselling Pink Floyd album. Now, the moon’s far side is the site of a global hunt for frozen water, with a Canadian-designed lunar rover leading the charge.

Geologists have long theorized that in the moon’s south polar region straddling its near and so-called dark sides — “dark” meaning unknown — there’s likely ice in the permanently shadowed craters. In 2009, instruments aboard numerous spacecraft detected deposits of water molecules, a suite of discoveries made by multiple space agencies that expanded the realm of possibilities for humans on the moon. It could make the moon an appropriate launch point for missions to send us even deeper into the solar system.

As early as 2026, the small but mighty Canadian Space Agency rover will touch down on the jagged, deeply cratered terrain of the moon’s south polar region to brave its extreme temperature swings in search of “water ice” — as opposed to other kinds of ice, like dry ice (frozen carbon dioxide). Built by Canadensys Aerospace, in partnership with others, the rover has six specialized scientific instruments to collect data. A team of researchers from five Canadian universities, and a few American institutions, led by Gordon Osinski from Western University in London, Ont., will analyze the information they gather. They’ll be able to investigate the composition of the lunar soil for signs of water ice, explore the region’s geology, and measure solar radiation to determine how it could affect human health.

Canada is also a key partner in NASA’s Artemis program of crewed lunar missions. NASA is tentatively scheduled to launch the Artemis II mission in November 2024 on a journey that will see Canadian Space Agency astronaut Jeremy Hansen take to the skies along with three NASA astronauts on the first crewed spacecraft to go beyond low Earth orbit since Apollo 17 in 1972.

The Canadian-led rover mission “really is a big first for Canada,” says Osinski. “Having a Canadian astronaut fly to the moon is absolutely huge. But having the first-ever Canadian-led planetary mission is also a big deal.”

The biggest challenge for the rover will be surviving the south pole’s harsh conditions, which include frigid -200 C lunar nights and scorching 100 C days, Osinski says. While he is hoping they can get a few months’ worth of research — just a few days on the moon — out of the rover, getting through just one long lunar night would qualify as a worthy accomplishment. “After a while, things are just not going to work at -200 C,” he explains. “It is way more challenging to have a rover in a polar region of the moon than it is on Mars.”