Have you ever thought about what is under the ice on Mars? No? Well, NASA has, ever since they detected a lake in 2018 they have not stopped investigating and proposing theories about what could be down there. You know why, right? Ice is water, and water… the source of life, that is where we come from!

Well, for many years, the south pole of Mars kept scientists focused on research, but now, a new analysis from the Mars Reconnaissance Orbiter (MRO) points to that “subterranean lake” probably not being a lake, nor subterranean, nor liquid. None of that. What would be down there is… rock. What a disappointment. Rocks or very compact sediments that, because of how the radar waves bounce, gave a signal that fooled even the most cautious.

It sounds a bit disappointing, yes. But the story does not end there,

The origin of the mystery

In 2018 the MARSIS radar (from the European Mars Express mission) captured an extremely bright signal under the south pole. It was exactly the kind of echo that, here on Earth, we associate with liquid water trapped under ice, and many automatically began to believe it could be a lake, that there could be life, and even that it could be a future water supply for human missions (we cannot drink tap water in some neighborhoods but they believed we could drink water from a Martian lake). Everything fit… more or less.

The problem came when NASA’s radar, SHARAD, scanned the same area and did not see anything like it. Nothing.

NASA returns to the exact point…

The SHARAD team wanted to try a maneuver called “very large roll”, basically rotating the spacecraft about 120 degrees so the radar would avoid the noise produced by the orbiter’s own structure.

Did it work? Yes. For the first time in almost two decades, SHARAD managed to look so deep under the ice. And well, it found several things, first that the bright echo from 2018 did not appear anywhere, and the surrounding area did not seem strange at all.

So, seeing all this… it is very hard to maintain that theory.

So… was everything a mistake?

Not exactly. It was more like an illusion, an interpretation that was too optimistic based on the data available at that time, just like when you believe the words of your almost-something one day before he or she ghosts you…

This is how science works, advancing, correcting, refining… even if it makes us sad that these theories are not confirmed.

A new path

The good thing is that this obsession has made new techniques possible for other purposes, for example knowing where there really is ice that could be used. And from that, the future of Mars would be underway, they could find drinkable water, oxygen… think about crops… Surely rent is cheaper on Mars than in NY!

SWIM

With the radar now refined, NASA is focusing on finding accessible ice in areas where an astronaut could live. And that is where SWIM (Subsurface Water Ice Mapping) comes in, a project that combines data from half of Mars:

Mars Reconnaissance Orbiter
Odyssey
Mars Global Surveyor

And with that they are creating a super precise map to find ice near the surface. Zones like Arcadia Planitia and Deuteronilus Mensae.

New study zones and future radar missions

The success of the “very large roll” has encouraged scientists to try the trick in other interesting regions, like Medusae Fossae, a huge equatorial place that returns very strange signals. It would be great to know if there are volcanic sediments there… or a massive hidden ice reserve, who knows?

And as if that were not enough, NASA is also working with Italy, Canada, and Japan on the Mars Ice Mapper, a satellite completely dedicated to finding useful ice with millimetric precision.

Let this serve as advice: when something does not turn out the way you expect, it is because there is still something better to discover!