NASA's Orion spacecraft is back on Earth after its flight around the Moon.
Why it matters: The uncrewed capsule's splashdown in the Pacific brings the space agency's first Artemis mission to a successful end, testing out some of the technology needed to one day send people to the surface of the Moon.
A world hurtling toward a frighteningly hot future is driving interest in geoengineering — unproven, controversial technologies with a sci-fi flavor that could temporarily freeze global warming in its tracks but not solve the underlying problem.
Why it matters: Ethical, geopolitical and practical considerations must be wrestled with regarding solar radiation management, or SRM — the most discussed and researched method of geoengineering.
