Millions of miles out into the solar system, a probe travels in orbit around Mars. Launched in June 2003, it has been circling the Red Planet ever since, beaming back images of the alien terrain below. But the craft has captured one series of images in particular that captivated the world – and you might find the explanation behind them difficult to believe.
Ever since it left Earth, the Mars Express mission has been revealing staggering truths about the mysterious planet. Then in December 2018 researchers on the ground announced another fascinating revelation. Over the course of several orbits, you see, the probe had put together a picture of a unique landmark known as the Korolev Crater.
In the Vastitas Borealis – or northern waste – region of Mars, the landscape is low-lying, with sparse features and gently sloping plains. But rising up in the area is the Korolev Crater – a vast depression stretching for 50 miles. In fact, the hollow is large enough to contain the volume of North America’s Lake Erie five times over.
Located on the swathe of land that encircles the northern pole of Mars, the Korolev Crater has been known to researchers for decades. But when the Mars Express beamed its images back to Earth, specialists were finally able to take a closer look. And in the photographs, something astonishing was revealed; a discovery that could bring us closer to understanding the Red Planet.
Prior to June 2003 the race to explore Mars was being fought mostly between Russia and the United States. In fact, in 1964 the NASA spacecraft Mariner 4 became the first to perform a successful flyby across the planet. Then, seven years later, the Soviet Union probe Mars 2 took things to the next level.
Yes, in 1971 Mars 2 cemented its place in history as the first piece of human technology to land on the Red Planet. But even though many more missions have been launched since then, only a handful have been successful. However, in 2003 the European Space Agency, or ESA, finally threw its hat into the ring.
And this is perhaps more surprising as the ESA was founded way back in 1975. The institution was established to further the role of Europe in exploring the universe beyond planet Earth. And after nearly three decades, the organization was ready to launch its first ever mission to another planet. Apparently, the craft involved was built quicker than any other like it – earning it the name Mars Express.
According to the ESA, the Mars Express’ missions were manifold. Along with capturing high resolution images, the craft was also tasked with mapping and measuring conditions on the surface. Meanwhile, a separate lander – dubbed Beagle 2 – would collect data from the planet itself.
In order to deliver on its mission, the Mars Express was loaded up with a whole host of impressive equipment. The craft was fitted with a High Resolution Stereo Camera (HRSC), for instance, to map the topography of the planet in great detail. Elsewhere, infrared and ultraviolet technology was installed to help the unmanned mission observe the alien conditions.
So with this array of equipment in place, in June 2003 the Mars Express took off from Kazakhstan, propelled into space by a Russian launcher. The Red Planet was located as close as possible to Earth at that time – a set-up that happens roughly once every two years. And so, it seemed the perfect opportunity for the probe to attempt the lengthy journey.
Happily, the flight proved a success, and the Mars Express entered the Red Planet’s orbit on Christmas Day of that year. Initially, the craft traveled in an elliptical pattern that completed one journey around Mars every 7.5 hours. Then, in January 2004 it settled into a polar orbit that takes around nearly seven hours to complete.
From the Mars Express’ position in orbit, the craft started to feed information back to observers back on Earth. And almost immediately, the revelations began. For instance, in 2004 the ESA announced that it had discovered water ice at the planet’s southern pole.
But the following month the mission suffered an unfortunate blow: the ESA informed the public that Beagle 2 had failed to land on the surface of Mars. However, the orbiter continued its work, and the following month another discovery was made when experts recorded the presence of methane in the planet’s atmosphere.
In the years since, then, the Mars Express has continued to open our eyes to a world that exists millions of miles from our own. And thanks to the high-tech camera equipment on board, ordinary citizens have been treated to a mind-boggling array of images. From vast craters and volcanoes to endless valleys of red rock, it’s truly a landscape that has to be seen to be believed.
However, perhaps the most fascinating aspect of the mission has been the opportunity that it’s given us to learn more about Mars’ atmosphere. And although scientists have long suspected that water ice could be found there, the data collected by the orbiter has allowed them to build upon this theory.
For instance, in 2005 the ESA announced that it had discovered hydrated minerals on Mars. And according to experts, this signals that conditions on the planet were once far wetter than they are now – meaning that the atmosphere may once have been conducive to life.
On another occasion, meanwhile, the orbiter detected clouds formed from carbon dioxide hovering 60 miles above the surface of Mars. Consequently, experts believe that this makes them the highest example of the phenomenon ever observed above a planet.
And the Mars Express also revealed some new data about the volcanoes that first erupted on Mars billions of years ago. It is estimated that they may have been active as recently as a few million years ago, and evidence suggests that the structures could have been flanked by glaciers up until a relatively recent time.
Elsewhere, almost 6,000 miles from the surface of Mars, another astronomical body caught the attention of the Mars Express. Over the course of many orbits, you see, researchers were able to study a moon called Phobos in greater detail than ever before. Interestingly, they have theorized that the interior is porous and that the satellite may be comprised of Martian debris.
Over time, researchers have also built up a picture of just how much frozen water is present on the Red Planet. And thanks to the Mars Express, they may have a staggering answer; apparently, there is enough ice in the planet’s polar caps to submerge the entire planet to a depth of over 35 feet.
Up until recently, though, perhaps the most startling discovery made by the Mars Express happened in the summer of 2018. In June of that year, researchers announced that they had found liquid water beneath the planet’s southern pole. If confirmed, these findings would represent a once-in-a-lifetime revelation – as well as the chance to learn more about potential life on the Red Planet.
Interestingly, the Mars Express is not the only mission to have discovered water on Mars. For instance, in 2013 researchers at NASA announced that the rover Curiosity had stumbled across something exciting. Yes, in the depths of the Gale Crater in the planet’s southern hemisphere, they apparently found evidence that the region was once a lake.
And the same agency subsequently made another discovery a mere three years later. NASA announced that it had found a large mass of frozen water beneath the surface of Mars. In fact, the anomaly was equivalent in volume to Lake Superior – one of the largest lakes on Earth.
In 2019 NASA then announced another fascinating piece of data about water on the Red Planet. Using radar technology on board the Mars Reconnaissance Orbiter, researchers had detected the presence of vast underground ice sheets. Submerged in layers of sand, these frozen masses are thought to stretch for nearly a mile beneath the surface. And apparently, their presence suggests that the planet’s ice caps once shifted – just like those on Earth.
Researchers had believed that Mars’ ancient ice had all but disappeared from the planet. But with this new discovery, they realized that much of it was actually preserved beneath the surface. Sheltered by a layer of sand, they theorized, the frozen sheets had made it through the warming of the atmosphere intact.
Amazingly, researchers also believe that a vast amount of water is contained within these sheets alone. After the Mars’ polar caps, it is probably the third largest reserve on the entire planet. And if these sheets were to melt,the entire surface of Mars would be submerged in approximately five feet of liquid.
According to Stefano Nerozzi – a graduate research assistant from the Institute for Geophysics at the University of Texas – these discoveries are significant. He told the Daily Mail in May 2019, “Understanding how much water was available globally versus what’s trapped in the poles is important if you’re going to have liquid water on Mars. You can have all the right conditions for life, but if most of the water is locked up at the poles, then it becomes difficult to have sufficient amounts of liquid water near the equator.”
Back at the ESA, researchers presumably must have felt the same excitement when studying the latest images from the Mars Express. The craft was able to capture a number of stunning photographs of the Korolev Crater using its high-resolution camera. And what these pictures revealed has enchanted observers around the world.
The camera on the Mars Express is capable of rendering images in staggering detail. In standard mode, it can capture features on the surface of the planet that are as little as 32 feet wide. Conversely, with its more specialized setting, it is able to interpret landmarks less than seven feet across.
In order to create its stunning photograph of the Korolev Crater, the ESA used snapshots from five separate orbits of Mars. Stitched together, they form something known as a mosaic image. And in December 2018 the organization released the incredible results to the public. According to many, the festive timing was perfect – since the landmark was filled with a glistening lake of ice.
For instance, the German Aerospace Center called the incredible discovery a “winter wonderland in red and white” on its website in that month. But how exactly did this vast lake of ice form on such an inhospitable planet? Well, according to experts, the key is in the tall lip of the crater which stands high above the plains of Vastitas Borealis.
You see, the air on Mars is much thinner than it is on Earth, and when it travels over the lip of the crater, it can become caught inside. And the air then proceeds to cool, eventually forming a layer of insulation within the crater. Below it, the ice remains protected from warmer temperatures and does not melt.
Today, the frozen lake inside the Korolev Crater is a staggering 530 cubic miles in volume. And in the middle of the crater – where the ice is at its thickest – it measures over a mile in depth. Researchers also believe that the feature exists all year round, too, even though Mars has warmer and colder seasons just like Earth.
Planetary geologist Kirsten Siebach from Houston’s Rice University explained to NBC News MACH in 2018 exactly how the ice managed to maintain its freezing temperature. She said, “This particular crater is very close to the polar ice cap, and the inside of the crater is at a lower elevation and more shadowed, so it creates a cold trap where the ice is stable.”
“There used to be liquid in rivers and lakes on Mars, but it largely either froze as the atmosphere dissipated or was lost to space about three billion years ago,” Siebach continued. “Ice still exists on Mars near the poles, and the Martian atmosphere has a tiny amount of water vapor.”
Yet although these recent images have propelled the Korolev Crater into the spotlight, it was first discovered during NASA’s Mariner program. Active for 11 years from 1962, this mission saw a series of probes sent out into the solar system. And over the course of a decade, they recorded fascinating information about Mercury, Venus and Mars.
In 1973 the newly discovered crater on Mars was named after Sergei Korolev – a rocket designer from the Soviet Union. At the time, he was virtually unknown around the world thanks to government secrecy, but the scientist was responsible for many trailblazing developments. For instance, he helped send the first living creature into space.
One day, will people like Korolev to able to send humans to inspect his namesake crater in person? Well, while that moment seems far away, images like those captured by the Mars Express come a close second best. The data collected by the ESA’s probe has proved incredibly valuable over the years, and its mission has been extended until at least 2020.
Elsewhere, the ESA is preparing the next stage of an even more ambitious mission. First launched in 2016, the ExoMars program aims to establish whether or not life ever existed on Mars. And in 2021 their goal is to land a rover on the planet to hunt for ancient organisms that could be buried beneath the surface.
According to the ESA, the rover will search the northern pole of Mars for signs of life – the same region where the Korolev Crater is located. And if they are successful, this corner of the Red Planet will become even more famous. But for now, the magical snapshots of its frozen lake should be enough to take anyone’s breath away.
But what of other exciting discoveries on Mars? Well, there’s no shortage, as it turns out. Just take, for instance, a groundbreaking study from 2018, which revealed a stunning new find on the Red Planet. NASA’s robotic rover Curiosity had been meticulously recording data there, and one particular insight that it gave blew experts away.
Mars arguably illustrates a worst-case scenario for our planetary future. As with the Red Planet, will deserts one day engulf the Earth? The barren Martian landscape evokes a vision of a planet-wide mass extinction, after all. But it may also hold secrets about our primordial origins too. In fact, once upon a time, Mars was covered with water. And the findings of a groundbreaking new study suggest that the planet was even more Earth-like than previously thought.
In the 1970s NASA’s Viking program successfully landed two probes on Mars. This gave the world its first close-up glimpse of the Red Planet’s ominous, dust-filled surface. The probes – designed to analyze Mars’ physical composition – also took samples of the planet’s atmosphere and soil. Then, in 1993, NASA created the Mars Exploration Program (MEP) to further enhance our knowledge. This program deployed a range of rovers, landers and orbital crafts to fulfill its missions.
So in November 2011 NASA launched the Mars Space Laboratory (MSL) from Cape Canaveral. The MSL spacecraft then spent nine months traveling 350 million miles across the solar system. Then, upon reaching Mars, it deployed Curiosity – a large robotic rover. And in August 2012 Curiosity successfully touched down on the planet’s surface inside Gale Crater.
Curiosity had several mission objectives. Firstly, it aimed to study the planet’s climate and geological composition. It would also analyze how water may have influenced its geography and determine its suitability for human habitation and exploration. In fact, it would search the planet for evidence that it may once have been able to support organic life. The mission was only intended to last two years, but in 2012 NASA extended it until further notice.
Then in June 2018 the journal Science published the results of two groundbreaking studies. One concerned the presence of organic molecules that Curiosity had identified in the soil. The other provided new details about the atmosphere’s methane content. Both studies gave exciting new insights into the planet’s ancient landscape – and also suggested that Mars may once have supported life.
Specifically, Curiosity found organic molecules within sedimentary material at the bottom of a three-billion-year-old lake bed. The compounds included benzene, toluene and thiophene as well as small carbon chains – such as butene and propane. The quantities of these organic materials are around 100 times greater than those previously observed there.
To collect the molecules, Curiosity drilled into the lake bed. This allowed it to retrieve a sample of ancient sedimentary rock known as mudstone. The sample was then placed inside Curiosity’s onboard oven, which raises the temperature to between 932 and 1508 °F. The heat increase subsequently caused the organic molecules within the sample to vaporize. And from this, Curiosity was then able to detect and identify them.
Curiosity also measured the variation in methane levels in the Martian atmosphere over a period of nearly six years. The measurements indicate that methane levels increase during the planet’s summer and decrease in the winter. However, the source of the methane is unclear. It could, for instance, be coming from an organic source on the planet’s surface or an underground reservoir.
Chris Webster, one of the Science paper’s main authors and a researcher at NASA’s Jet Propulsion Laboratory, said the results were obtained thanks to Curiosity’s durability. “This is the first time we’ve seen something repeatable in the methane story,” he said. “This is all possible because of Curiosity’s longevity. The long duration has allowed us to see the patterns in this seasonal ‘breathing.’”
Meanwhile, the discovery of organic molecules in the planet’s rocks – as well as fluctuations in its atmospheric methane – has profound implications for our understanding of Mars. It could be that both phenomena are a sign of endemic carbon-based life forms, past or present. Indeed, the findings represent strong evidence of extraterrestrial life.
Speaking to The Guardian in June 2018, Kirsten Siebach, a self-professed “life-on-Mars sceptic” and geologist at Rice University, found the results encouraging. “These molecules could have been part of life, but they could also have been food for life,” she said. “To know that the water really was full of organic molecules really opens up the different ways that life could have existed on Mars.”
And according to Inge Loes ten Kate of the University of Utrecht in the Netherlands, the discoveries represent an astrobiology breakthrough. “The question of whether life might have originated or existed on Mars is a lot more opportune now that we know that organic molecules were present on its surface at the time,” she wrote in a companion article for Science.
Yet the scientific definition of “organic” is actually quite different to the common definition. Colloquially, organic means biological or living. Scientifically, though, “organic” refers to any compound that contains hydrogen and carbon – such as methane. So, by this definition, organic compounds are not necessarily biological; some are wholly or partly synthetic, such as plastics.
The presence of these organic compounds on Mars could therefore indicate biological life. Or they could be the result of other less exciting phenomena. In fact, no one knows the true source of the molecules. Natural processes, such as volcanic activity, may have created them. Alternatively, they may have arrived on the planet via a comet or a meteor.
But biogeochemist Jennifer Eigenbrode, who works at Maryland’s NASA’s Goddard Space Flight Center, still thinks the findings are promising. “The amazing consistency of the material makes me think we have a slam-dunk signal for organics on Mars,” she told The Guardian in June 2018. “It is not telling us that life was there, but it is saying that everything organisms really needed to live in that kind of environment, all of that was there.”
Ashwin Vasavada, a scientist working on Curiosity, argues that it’s now increasingly probable that NASA could uncover conclusive evidence of biological life. “The chances of being able to find signs of ancient life with future missions, if life was ever present, just went up,” he told The Independent in June 2018.
These days, NASA’s InSight lander, which touched down on Mars in November 2018, represents the agency’s latest effort to explore the planet. Its mission is to analyze the internal structure of Mars, including its core, mantle and crust. NASA will then be able to determine if Mars is “geologically active,” like Earth.
In 2020 NASA also intends to dispatch a new rover to the planet. Its specific goal will be to identify evidence of ancient microbes. This rover will have the capability of creating a cache of samples that can be later picked up by another craft and returned to Earth, where they can be thoroughly analyzed in laboratories that are too large to attach to a mobile unit.
Speaking to The Independent, associate administrator for NASA’s Science Mission Directorate Thomas Zurbuchen expressed hope for the future. “With these new findings, Mars is telling us to stay the course and keep searching for evidence of life,” he said. “I’m confident that our ongoing and planned missions will unlock even more breathtaking discoveries on the Red Planet.”