Sending a spacecraft to the far reaches of our solar system to mine asteroids might seem like an improbable ambition best left to science fiction. But it’s inching closer to reality. A NASA mission is underway to test the feasibility on a nearby asteroid, and a niche group of companies is ramping up to claim a piece of the pie.

Industry barons see a future in finding and harnessing water on asteroids for rocket fuel, which will allow astronauts and spacecrafts to stay in orbit for longer periods. Investors, including Richard Branson, China’s Tencent Holdings and the nation of Luxembourg, see a longer-term solution to replenishing materials such as iron and nickel as Earth’s natural resources are depleted.

Millions of asteroids roam our solar system. Most are thought unsuitable for mining, either because they’re too small, too inaccessible to Earth or because the materials that make up the asteroid have little value. But we know of almost 1,000 asteroids that show potential. Timing is everything, though. The varied orbits of these asteroids mean that many are nearby only once every several years.

Neutron stars aren’t the twinkle-twinkle kind you typically see in the night sky. They’re stellar corpses, and incredibly dense sources of gravity, with perhaps 1.5 times the mass of the sun packed into an area less than a dozen miles across. Around 9,000 light years away from Earth, one neutron star seems to have befriended a red dwarf. And scientists observed the new relationship beginning in a flash of energy.

An international team of researchers first spotted what looked like the symbiotic relationship of an old red dwarf star waking up a neutron star on August 13, 2017, using an Earth-orbiting telescope called INTEGRAL. While binary stars are common, lots of things about this finding, from capturing the initial blast that signaled the start of the stellar relationship, were a surprise.

“It was a very exciting find,” study author Arash Bahramian from Michigan State University told Gizmodo, “Especially given that it’s rare to see the start of the process.”