NASA says it has big news for us Monday. "Mars Mystery Solved," the agency's news release touts without offering even a hint as to what mystery they mean.
For those who just can't wait, a little Googling may solve the puzzle -- and it's not Matt Damon, little green people, or any other clear indication of life. It appears to be a confirmation of periodically flowing water on the planet's surface.
Three of the scientists slated for the news conference are listed as authors of a new paper to be delivered at this week's European Planetary Science Congress.
In it, the researchers say analysis of imaging from the Mars Reconnaissance Orbiter proves that seasonal dark streaks on the Martian surface are the result of briny water periodically flowing across the planet's surface.
The confirmation of water on the surface of Mars would be important and would raise a host of questions, chief among them: Where is the water coming from, and what doesit mean for the prospect of life, past or present?
The paper doesn't answer those questions, and NASA isn't talking ahead of its Monday morning news conference. Neither the agency nor the paper's authors responded to requests for comment Sunday.
If Monday's announcement isn't about this specific paper, it's still likely to have something to do with water: in the soil, underground or in the atmosphere. Not only is the question of water there a hot topic for research, at least two of the authors have been heavily involved in the hunt: Alfred McEwen and Lujendra Ojha.
Both were in on the initial discovery of the dark streaks back in 2011.
But whatever NASA appears ready to announce, it looks to fall short of the breathless headlines in some media outlets suggesting the NASA may have found life on the red planet, or the endless, often absurd, speculation on social media -- home of the the Mars bunny, lizard, and myriad other claims based on photos sent back from the planet.
Researchers have known Mars has water for many years, based on everything from photographic evidence of structures that look like riverbeds to results of scientific experiments performed aboard landers sent to the red planet.
And some have theorized for years that dark streaks -- formally called recurring slope linae -- that show up on the surface when it's warmer and fade when it's cooler suggest the presence of flowing water. In fact Ojha suggested that very mechanism in explaining his 2011 discovery but said it could be tough to prove.
Ojha is the primary author on the new paper, in which the researchers say analysis of spectral imaging from a tool aboard the Mars Reconnaissance Orbiter proves the streaks are in fact caused by salty water flowing downhill.
The salt content of the water is important because without it, the water would freeze in Mars' bone-chilling temperatures.
The water could be coming from subsurface ice, from salts attracting water from the thin Martian atmosphere or possibly bubbling up from an aquifer, the researchers say.
In April, McEwan announced research showing that salts in the Martian soil have the ability to grab enough water out of the air to form tiny puddles at night. And in March, NASA said Mars may once have had a sea similar to the Atlantic Ocean on Earth. About 87% of that water has been lost to space, researchers said.