It's a technology that doesn't even exist yet, but its effects could be so drastically destructive that scientists in the field are calling for it to be banned now, before it's too late.

We're talking, of course, about "mirror life" — synthetic organisms that quite literally turn natural biology on its head.

"We should choose not to build mirror life and pass laws to ensure nobody can," John Glass, a synthetic biologist who helped create the first living cell with a synthetic genome, wrote in a speculative yet terrifying piece for the Financial Times. "The question is not whether we are able to prevent this threat — it is whether we will act while we still can."

Mirror lifeforms contain DNA structures that are the mirror image to all known organisms. In all life on Earth, the DNA double helix is right-handed, meaning its strands, a sugar-phosphate backbone, twist to the right. (If you make a thumbs-up with your right hand, the vertical axis would be aligned with your thumb, while your fingers represent the curl of the spiral.) The opposite is the case for proteins, the building blocks of cells, which are left-handed.

This so-called homochirality is true for all known lifeforms. So what happens when humans engineer a synthetic organism where its DNA twists to the left, while its proteins twist to the right?

The scary thing is that we can't say for sure — but many biologists fear the worst. In December, a group of leading figures in the field, including two Nobel laureates, published a massive technical report warning that the consequences of mirror life "could be globally disastrous," possibly even wiping out all life if the new organisms prove pathogenic to existing life, like us humans.

In June of this year, more than 150 scientists and ethicists echoed these concerns in a conference at the Institut Pasteur in Paris to weigh the risks of developing the tech. "It was something I never expected to see in my scientific career," Glass wrote. He noted that the Alfred P Sloan Foundation, an influential nonprofit organization that funds scientific research, has been unequivocal that it will not support efforts to create mirror organisms.