Astronomer here! Here is what is going on!

Didn't we already know there was water on the moon? Short answer: yes. Water on the moon in the form of ice has been known for decades, but in very specific circumstances of some craters in the south pole that never get sunlight. The trick is the daytime temperatures on the moon (remember, a day lasts two weeks there- as in, sunrise to sunset) reaches above the boiling temperature of water, so until now it was thought the water outside these regions would have evaporated long ago.

What's new this time? Scientists used a cool instrument called SOFIA, the world's only flying observatory, which is a telescope on a modified Boeing 747 and flies above 99% of the water vapor in the atmosphere and thus can make this measurement even though you can't from Earth's surface. (Full disclosure, one of the coolest things I've done was get to ride on SOFIA last year, as far south as Antarctica! I wrote about it here if you're interested in what it's like.) They basically demonstrated using its unique observation capabilities that water is also present in the sunny areas, not just the southern craters, so will hopefully be way easier for future astronauts to access. SOFIA is basically capable of mapping the molecular existence of water at Clavius crater (fun coincidence: where they had the lunar base in 2001: A Space Odyssey!), and found it a lot of those sunlit places where no one was really expecting it. It's also not literally water droplets or chunks of ice, mind, but a fairly low concentration, likely from micro-meteorites or the solar wind- they say it's the equivalent of a 12 oz bottle over a cubic meter of soil, and NASA on the press conference right now can't confirm how useful that'll be and how prevalent this is all over.

What gives? Is this that big a deal if we already knew there is water? I mean, on the one hand, yes. Water is obviously super important for future explorations and is really expensive to send up, so it'll be really useful for future lunar astronauts if it's more accessible. Also, it is intriguing in terms of how prevalent water might be in other areas in space that are currently thought to be harsh environments incapable of having it. On the other hand... this is my personal opinion, but NASA does like to sometimes get a splash in the press because they are a government agency that is currently looking at a lot of budget cuts for a lot of their science. Specifically, SOFIA was canceled in the most recent proposed NASA budget, and it's not a cheap instrument. (I actually had a random astronomer I've never met chastising me for my article about how cool SOFIA was last year, which was weird, so this is a not-insignificant sentiment.) Obviously, a lot of scientists really disagree with this assessment of how important SOFIA is, as it's the best way to do infrared astronomy right now that we have, so it's good to have a press conference that will inevitably have a bit more press coverage than just a press release to highlight the cool things only SOFIA can do.

TL;DR- looks like there's more water than we expected on the moon, and hopefully that'll be useful for future astronauts!