Scientists have long suspected that Mars was once warm and wet in its ancient past. The Mars Ocean Hypothesis says that the planet was home to a large ocean around 4 billion years ago. The ocean filled the Vastitas Borealis basin in the planet’s northern hemisphere. The basin is 4–5 km (2.5–3 miles) below Mars’ mean elevation.
A new topographic map of Mars reinforces the hypothesis and adds more detail.
The existence of water on Mars is a contentious subject. We know there used to be water on the surface of the planet, though it’s long gone now. We know there’s frozen water underground in the world, and we know there’s water vapour in the air. But life needs liquid water.
Could there be liquid water on Mars?
A new study shows how salty water could emerge from the atmosphere onto Mars’ surface under the right conditions.
The HiRISE (High-Resolution Imaging Science Experiment) camera on the Mars Reconnaissance Orbiter has captured another beauty. This time the image shows water ice peeking out from a cliffside on Mars. A layer of sediment obscures most of the ice, but fingers of it are visible.
Mars and water. Those words can trigger an avalanche of speculation, evidence, hypotheses, and theories. Mars has some water now, but it’s frozen, and most of it’s buried. There’s only a tiny bit of water vapour in the atmosphere. Evidence shows that it was much wetter in the past. In its ancient past, the planet may have had a global ocean. But was it habitable at one time?
A new study says it wasn’t. Mars lost most of its water, and it’s all to do with the planet’s size.
Dust on Mars gets everywhere – including on top of ice deposited during one of Mars’ previous ice ages. Just how that dust affects the ice is still up for some debate. Adding to that debate, a recent paper by researchers at Arizona State University and the University of Washington has laid out a map between the dust content of a glacier and the brightness of its ice.
One of the hardest things to reconcile in science is when new data either complicates or refutes previously findings. It’s even more difficult when those findings were widely publicized and heralded around the community. But that is how science works – the theories must fit the data. So when a team from JPL analyzed data from Mars Express about the Martian South Pole, they realized the findings announced in 2018 about subsurface lakes on Mars might have been more fraught than they had originally thought.
Changes in Mar’s geography always attract significant scientific and even public attention. A hope for signs of liquid water (and therefore life) is likely one of the primary driving forces behind this interest. One particularly striking changing feature is the Recurring Slope Lineae (RSL) originally found by the Mars Reconnaissance Orbiter (MRO). Now, scientists at the SETI Institute have a modified theory for where those RSLs might develop – a combination of water ice and salt just under the Martian surface.
A little over a decade from now, NASA plans to send astronauts to Mars for the first time. This mission will build on decades of robotic exploration, collect samples from the surface, and return them to Earth for analysis. Given the immense distance involved, any operations on the Martian surface will need to be as self-sufficient as possible, which means sourcing whatever they can locally.
This includes using the local water to create oxygen gas, drinking water, and rocket fuel, which represents a challenge considering that any liquid water is likely to be briny. Luckily, a team of researchers from the McKelvey School of Engineering at Washington University at St. Louis (WUSTL) has created a new type of electrolysis system that can convert briny water into usable products while also being compact and lightweight.