A total lunar eclipse provided a spectacular celestial show as it unfolded Sunday night into early Monday in the Americas.

The eastern half of North America and all of Central and South America were prime locations to see the eclipse, while partial stages were visible across Africa, Europe and the Middle East.

Among those watching the eclipse where skies were clear were residents of Buenos Aires, Argentina, who bundled up in the chilly night and relaxed on blankets in a park to look at the event. In Caracas, Venezuela, some people brought laser pointers as a crowd gathered to watch.

Before this decade is over, NASA will send astronauts to the moon for the first time since the Apollo Era. As part of the Artemis Program, NASA also plans to establish the infrastructure that will allow for a "sustained program of lunar exploration." A key part of this is the Lunar Gateway, an orbiting space station that will facilitate regular trips to and from the lunar surface. In addition to being a docking point for ships going to and from Earth, the station will also allow for long-duration missions to Mars.

The Gateway will have what is known in orbital mechanics as a "near rectilinear halo orbit" (NRHO), meaning it will orbit the moon from pole to pole. To test the long-term stability of this orbit, NASA will be sending the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) to the moon by the end of May.

Like Earth, planetary bodies such as the moon, Mars, asteroids and comets contain substantial deposits of valuable resources. This has caught the attention of both researchers and industry, with hopes of one day mining them to support a space economy.

But setting up any kind of off-Earth mining industry will be no small feat. Let's look at what we're up against.

In-situ resource utilization

When you think of off-Earth mining, you might imagine extracting materials from various bodies in space and bringing them back to Earth. But this is unlikely to be the first commercially viable example.

If we wanted to establish a permanent human presence on the moon, as NASA has proposed, we would need to resupply astronauts living there. Resources such as water can only be recycled to an extent.

At the same time, resources are extremely expensive to launch from Earth. As of 2018, it cost about A$3,645 to launch one kilogram of material into low Earth orbit, and more to launch it higher, or onto the moon.