The density of space junk peaks around 620 miles up, in the middle of so-called low-Earth orbit. That’s bad, because many weather, scientific, and reconnaissance satellites circle in various low-Earth orbits. But that height also offers an opportunity. Below about 560 miles, small objects start to feel a significant drag from the Earth’s upper atmosphere. This drag causes them to slowly spiral toward Earth, and they eventually burn up in the atmosphere. The tungsten cloud could theoretically provide extra drag on objects orbiting above the 600-mile mark, slowing the itty-bitty debris down enough to fall below the 560-mile threshold. Tungsten wouldn’t clear up space instantly—objects at 560 miles can still circle for decades. But that’s vastly better than the centuries-long orbits of fast-moving objects even a little higher.

That said, there could be a downside to sending 20 tons of heavy metal dust aloft. Eventually, the tungsten cloud would itself fall toward Earth. Tungsten isn’t acutely toxic, and Ganguli and friends argue that, spread over many years, all that dust would not amount to much, especially compared with the hundreds of tons of micro-meteors and other space dust that already flits down onto Earth each day. But their five-page paper outlining the tungsten cloud devotes 54 words to the potential environmental impact, hardly an exhaustive look. Astronomers might also object, because the dust could interfere to an unknown degree with light streaming toward Earth from space. Fighting through swarms of microscopic dust could give satellites fits, too, though again, the naval scientists argue the impact would be negligible. (Most satellites point their instruments either straight down toward Earth or straight out into space, and therefore away from what would be mostly horizontal streams of tungsten dust.)

These scenarios all assume, though, that the tungsten dust will behave, and that the ionosphere or solar wind or whatever else won’t interact with it in funny ways. For instance, what if the tungsten doesn’t disperse in nice soft poofs but clumps together? Something similar happened with Project West Ford, a Cold War operation in the early 1960s to improve the reliability of radio communication (in case the Soviets sabotaged our undersea cables) by giving transmitters something solid to bounce signals off in space. To howls worldwide, the U.S. injected 480 million inch-long copper needles into orbit, clusters of which still circle Earth. Or, some observers have suggested that the dust could swell outward—perhaps even form a Saturn-like ring of Element 74 around Earth.

So, yeah, the idea still needs polishing. But if the growing amount of space junk wipes out a few billion-dollar satellites soon, a silvery tungsten cloud could be the least of many evils.

The worms in question were of the species Caenorhabditis elegans, and were supplied by boffins at Nottingham uni having originally been found browsing a dump in Bristol. Many of C elegans’ genes perform the same function as those in humans, and the scientists wanted to see if RNA interference therapy (RNAi) could be used to fight the serious loss of muscle which astronauts are subject to during long spaceflights.

Some millions of the worms were sent up aboard space shuttle Atlantis on the STS-129 mission in 2009, and subsequently treated in the station’s Japanese-built “Kibo” lab podule. They were subsequently brought back to Earth on the next shuttle to visit, Endeavour (now retired), executing mission STS-130.

“It was really a quite straightforward experiment,” says Nottingham uni’s Dr Nathaniel Szewczyk. “Once the worms were in space the scientists onboard the International Space Station treated them with RNAi and then returned them to us for post flight analysis.

"These results are very exciting as they clearly demonstrate that RNAi can be used effectively to block proteins which are needed for muscle to shrink.”

Szewczyk’s colleague and fellow space garbage-worm gene therapy boffin, Dr Timothy Etheridge, added: “We were very pleased… our experiments allowed us to demonstrate that this form of gene therapy works effectively during spaceflight. The unexpected finding that RNAi can effectively block protein degradation in muscle in space was also a very welcome surprise.”