These ions are created when charged particles from the Sun pelt the lunar surface, causing particles there to react and become negatively charged. Here on Earth, the planet's magnetic field stops these particles from ever reaching the surface.
But since the Moon doesn't have a magnetic field, its surface is extremely vulnerable to these charged particles. Unlike positively charged particles, however, they never make it back into orbit, forcing scientists to study them on the surface instead.
Important to know if we ever want a moonbase. Its always been known that ionizing radiation would be an issue without an atmosphere, but this is more solid evidence that they are present on the surface. They also can do cool stuff at the atomic level to form ionic bonds and create thing naturally that we just wouldn't find here on earth.
The next step is to send humans to lick them and see if they taste good. Licking the lunar surface could reveal flavors never experienced by man or beast.
Thanks, but yeah, the article just says the following:
The observations could have considerable implications for our understanding of what goes on in other spots in our celestial neighborhood that aren't protected by a magnetic field either.
"These observations on the Moon will help us better understand the surface environment and act as a pathfinder to explore negative ion populations in other airless bodies in the Solar System," NILS principal investigator Martin Wieser explained in the statement, "from planets to asteroids and other moons."
It doesn't really say why negative ions are significant, just that they are found in places without a magnetic field and may help us understand similar places. The research seems more in-depth, and the article send to lack important details.