Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
By Cosmos
Mars has always been a source of wonder. What secrets does the Red Planet hold? This year saw more developments in our understanding of our planetary neighbour thanks to a new team of rovers currently surveying the planet’s surface. Grab a telescope, and join us as we recap some of the awesome Mars discoveries that Cosmos has covered in 2022.
1. What does Mars sound like?
NASA’s Perseverance has recorded the soundscapes of Mars. Like an overly-keen love interest, the plucky car-sized rover has been incessantly sending back mixtapes of its recordings.
With a very thin atmosphere, Mars doesn’t have much by way of audible weather events. Oh, and there was no alien chatter either, in case you were wondering. At one point it was so quiet, scientists were wondering if the microphones were broken.
But there were some sounds of scientific note.
The playlists have included dust devils, differing sound speeds depending on frequency, and evidence that the Martian soundscape is seasonal. Keep your ears pealed for the next Martian Hottest 100, I say.
2. Molten magma hiding beneath the Martian surface
Mars is like Earth in many ways, but cold and dead inside. Kind of like the Daria of the solar system. Or so we thought.
Seismic activity measured by NASA’s InSight lander revealed that there might actually be pockets of molten lava beneath the surface of the Red Planet. A marsquake (an earthquake, but on Mars) showed that a pocket of material beneath Mars’s crust did not behave like solid rock, but like a goo – suggesting that it was molten.
Volcanism like this might indicate that certain parts of Mars (perhaps deep underground) might be hospitable for life. Martian lizard people, perhaps?
The same dataset was used to confirm the size of the Red Planet’s core. It’s 3,620 kilometres in diameter by the way.
3. Models suggest there could have been life
We’re obsessed with the prospect of finding life on Mars – dead or alive. But, in the absence of direct evidence confirming the existence of organisms on the Red Planet, sometimes it’s enough just to ask the question: was it even possible? The imagination is free to run wild from there.
This is exactly what French researchers did in 2022.
Using advanced computer models to show that around 4 billion years ago Mars’s surface would at least periodically have supported liquid water.
Their study also shows that the environmental and chemical conditions on Mars at this time, called the Noachian period, could have supported methane-producing life.
So, early Mars may have been home to flatulent microbial life 4 billion years before we were born. Good to know.
4. AI works out Mars meteorite’s origin
While we’re sending rovers to Mars, sometimes Mars makes its way to us.
One of the most famous Martian meteorites, “Black Beauty” was found in northern Africa in 2011. The 320g rock is the oldest Martian meteorite.
Researchers have used an artificial intelligence program to work out which of Mars’s many impact craters is the site of the collision which, millions of years ago, led to detritus making its way down to Earth in the form of Black Beauty.
The Pawsy Supercomputer in Perth, Western Australia found the impact site on the Red Planet, now called the Karratha Crater, named after the Pilbara city of Karratha – home to one of the oldest terrestrial rocks.
5. Liquid water! Yes! No! Maybe!
Like the question of weather red wine is good or bad for you, it seems that every new paper on the potential existence of liquid water on Mars seems to refute the claims of the previous one. But we all hold out hope that the Red Planet holds oases.
Such a find would greatly increase the chance that we’re not pitifully alone on this rock hurtling through space. There might be wet, green microbes on Mars with which we can communicate!
But the jury’s still out on whether Mars has liquid water on its surface. We know it used to, from the unmistakable impressions that rivers and oceans carved on the planet’s surface billions of years ago.
There was evidence of a sub-glacial liquid lake on Mars in 2018. The same researchers came back in 2022 with further evidence. Then that was refuted with an alternative explanation of the results. Then the refutation was refuted. I imagine that 2023 and beyond will see more of this toing and froing.