In the summer of 2003 the European Space Agency (ESA) launched a spacecraft devoted to observing Mars. And in the years that have followed, the mission has not only captured some incredible images of the Red Planet, but it has also made some vital discoveries. After seeing pictures taken in September 2018 from the craft, however, scientists may have initially been left baffled.
For millennia, Mars has been a source of fascination for humankind. In fact, the planet appears in writings by several ancient peoples, including the Mesopotamians, the Egyptians and the Greeks. It was not until 1610, though, that Mars was observed through a telescope, with noted astronomer Galileo Galilei becoming the first to see the celestial body in this way.
Mars is significant in other arenas beyond the astronomical too. In some cultures, for example, the planet serves as a representation of masculinity. And the symbol designated to Mars also doubles as a signifier for the male gender. Plus, of course, Mars was the god of war in Roman mythology, and the planet was later named in honor of the deity.
More recently, Mars has also inspired several pop-cultural works. Among the most enduring of these is the H.G. Wells novel The War of the Worlds, which sees Martians taking over Earth. The book was then famously brought to radio by Orson Welles, who presented the tale as a genuine newscast and so caused a panic among some of the listening public. Then in 2005 a Steven Spielberg-directed film version of The War of the Worlds was released, although this only took loose inspiration from Wells’ novel.
And while The War of the Worlds may be a work of fiction, the possibility of other beings existing on Mars has not been entirely ruled out. Today, investigations continue into the possibility of whether the planet could once have sustained life – and whether it could do so again – and some of the results look fairly promising.
For one, Mars is now known to contain water – mostly in the form of ice. Methane has also been detected in its atmosphere, which hints at the possibility of microorganisms living under the planet’s surface. And although neither of these discoveries necessarily point to life on Mars, they do suggest that some of the conditions there may be conducive to organisms existing.
Meanwhile, multiple spacecraft have been sent to study the planet. In fact, humans have been launching missions to Mars since the 1960s. And in 2018 there are two crafts on the surface of the planet as well as six in orbit around it – with one of these being the ESA’s Mars Express.
Mars Express was initially made up of both a lander and an orbiter; after reaching the atmosphere of Mars, though, the lander became uncontactable. Fortunately, the orbiter has been rather more successful in its duties as it charts the surface of the planet and snaps high-quality images.
The work of the Mars Express orbiter has uncovered a number of features on the planet for scientists to pore over. But when some images were captured in September 2018, they may have initially left experts stumped. You see, in the pictures smoke appears to be rising from Mars’ surface – even though fire cannot be created there.
In particular, the plume appeared to be close to a volcano known as Arsia Mons. And yet it’s been argued that the smoke’s proximity to Arsia Mons is a mere coincidence. For one, the volcano has been dormant for approximately 50 million years, and so an eruption can’t be to blame.
Nevertheless, conspiracy theorists have been quick to reach their own conclusions. One such individual claimed during a YouTube video that the smoke had emanated from an explosion – and that the event had since been deliberately concealed from the public. Meanwhile, a commenter on the clip suggested that the planet is being terraformed in preparation for human colonization.
But the ESA has its own theory for why the plume has emerged. According to the agency, the “smoke” is actually a water-ice cloud that has been condensing close to the volcano. As for how this phenomenon came into being in the first place? Well, apparently, it was made by way of a flow of air at the side of Arsia Mons, with this in turn creating what is known as a “lee cloud.”
Intriguingly, the size of the lee cloud appears to shift depending on the time of day. It gets longer throughout the morning, for example, and can grow so large that it may even be visible to Earthbound telescopes. And it’s said that the cloud may also have been impacted by dust particles.
It’s worth noting, too, that lee clouds have been witnessed above Arsia Mons in the past. The Mars Express mission and others have documented the phenomenon in 2009, then again in 2012 and 2015, for instance. But observations of water-ice clouds on Mars have been made even before that, as Cornell University researchers E. Z. Noe Dobrea and J.F. Bell attest to in a 2005 paper.
In the article for the Journal of Geophysical Research: Planets, the authors discussed occurrences comparable to the one observed by Mars Express. “We have also found evidence for similar persistent cloudiness… in this region, based on Hubble Space Telescope UV imaging,” they wrote.
It would appear, then, that the plume is more likely to be a lee cloud rather than evidence of an explosion or volcanic eruption. In any case, the event is worthy of scientists’ attention. And missions such as Mars Express allow for the necessary investigations to take place.
In fact, Mars Express has proven so successful in its purpose that its lifespan has been extended multiple times. The mission is now set to continue until at least 2020 – some 17 years after it was originally launched. What’s more, the Mars Express orbiter is already among the oldest spacecraft to still be in operation around the Red Planet – second only to 2001 Mars Odyssey.
It’s worth noting, though, that other missions focused on Mars are still active today. In 2013, for example, NASA launched the Mars Atmosphere and Volatile Evolution (MAVEN) mission in a bid to discover more about the planet’s climate and atmosphere.
Further spacecraft are likely to head to Mars too. For instance, the ESA and Russia’s Roscosmos aim to launch the solar-powered ExoMars rover in 2020. And in May 2018 NASA sent off a lander known as InSight. InSight is anticipated to reach Mars’ surface in late November 2018, and it will then hopefully investigate the planet’s interior.
As there are many ongoing and planned missions to and around Mars, then, we may yet glean even more information about the planet. And whether or not we ever discover proof of life on Mars, the celestial body is likely to continue capturing our imaginations for some time to come – especially when images like the ones made by Mars Express reach Earth.