How astonishing observatories could do big physics from the moon

When Michael Collins floated above the far side of the moon during the Apollo 11 mission in 1969, he knew he would be remembered as the loneliest human in history. He recalled feeling unafraid, almost exultant, thinking about everything on the other side of the moon: Neil Armstrong and Buzz Aldrin on the lunar surface and, beyond that, every creature on Earth and everything humanity had ever built. On his side, as Collins wrote in his memoir, was “one plus God only knows what”.

A half-century later, the famously empty lunar landscape is starting to get busier. Not only are NASA and other space agencies preparing to send humans to the moon for longer periods of time, researchers around the world are working on blueprints to turn it into the most powerful astrophysics laboratory in history. This could address the deepest questions we have ever asked. How did the first stars ignite? Why has the universe evolved the way it did? Is there anyone else out there?

“On the moon, we can think about concepts that, here on Earth, are completely impossible to realise,” says Jan Harms, an astronomer at the Gran Sasso Science Institute in Italy. The conditions there seem nearly purpose-built to house cutting-edge observatories that could answer some of the most perplexing questions about the cosmos. The moon’s unique peace and quiet, especially on the side that never faces Earth, could make it a portal to the history of the universe, from the first galaxies to the mysterious dark energy that stretches…