NASA announced (opens new window) ahead of time that it would be holding a press release about an important discovery. Lots of speculation, as always. Maybe life on mars, although no hardware to test properly for life on Mars.

seasonal hydrated salts detected when above -23c, would lower the freezing point of a liquid brine

shallow subsurface flow

magnesium perchlorate, magnesium chlorate and sodium perchlorate

identified from orbit

Extremophiles

Life finds a way

After NASA Announces It Found Water On Mars, Rush Limbaugh Says It's Part Of A Climate Change Conspiracy

"NASA [are] just making up the amount of ice in the North and South Poles, they're making up the temperatures, they're lying and making up false charts and so forth. So what's to stop them from making up something that happened on Mars that will help advance their left-wing agenda on this planet?"

"Don't know how long it's going to take, but this news that there is flowing water on Mars is somehow going to find its way into a technique to advance the leftist agenda. I don't know what it is, I would assume it would be something to do with global warming and you can -- maybe there was once an advanced civilization. If they say they found flowing water, next they're going to find a graveyard."

Source (opens new window)