“Is there life on Mars?” More than fifty years into the Space Age and there still is no definitive answer. Completing our series of posts on this mystery, we look at the latest ideas about the existence of beings on our neighbouring planet.
In the previous part of this series I described how serious scientists have made careful, in depth and hugely expensive studies of Martian rocks and soil to determine if micro-organisms lurk within. The result has been confusion, with most saying “no” to there being biology in the stones but some saying “yes”. However there are others outside the scientific community that say that all you need to find life on Mars is a comfy chair, a computer and an internet link. From the comfort of your own home (or bedroom in your mum’s house) you can scrutinise images of Mars and the evidence of life will be as plain as the nose on your face. And what life! Giant trees, giant worms, herds of animals, gorillas, sasquatches, fossils of dinosaurs and dragons have all been reported by amateurs. Then there are the ruined cities and monuments…
The first-reported and best known Martian “anomaly” is the Face on the plains of Cydonia. Remember the NASA Viking landers? Their motherships stayed in orbit around Mars taking images that were of great quality for the 1970s. On 25 July 1976, Viking 1 photographed a mesa about 2 km (1.2 miles) long. There are many such structures in the surrounding area (some resemble islands eroded by ancient, and now gone, waters) but this one stood out so much that it was mentioned in a NASA press release. In the photos a huge humanoid face wearing a headdress appeared to be blankly staring into the bleak Martian sky.
Despite the press release, the Face was more or less ignored but over the years knowledge of it gradually permeated public consciousness (I first heard of in Omni Magazine back when in the days when it was good). Amateur observers claimed it was an artificial monument, soon other structures, the “City”, the “Fortress” and the “D&M Pyramid” were found within 10km of the face. The vast majority of the scientific community ignored these claims and so were accused of being too stuck in their ways to consider the possibility or of being part of a Dan Brownesque conspiracy to suppress the evidence. A couple of books appeared on these landforms but it took the internet to really spread them around. Eventually the Face guest-starred in a first season episode of The X-Files and the disappointing movie Mission to Mars (2000). Inspired, others searched archives of images to find their own artifacts and organisms, finding giant glass worms and trees.
Sadly all of these are bogus. Yes, the Face exists but when higher resolution images of it were made (notably by ESA’s Mars Express, a probe that will appear again in this story) it could be seen to be an entirely natural crumbling heap of rubble. Needless to say, supporters of the artificial monument theory decried the new images, declaring them fake (while some claimed it was still a face, but an alien face)! None of the other alleged alien relics on Mars are regarded as anything but natural features by people who know what they are talking about.
I will try to be fair here, it is easy to look at some images of the Martian surface taken by landers and rovers and to convince yourself that it is a chilly version of Arizona, but it is an alien world and there are landscapes formed by processes that do not exist on Earth. Hence there are things to be seen on Mars which do not have an analogue on our planet. One example are the ‘trees’ reported by some, these are almost certainly channels cut in the surface by subliming carbon dioxide ice revealing darker material underneath. The technology which creates the images confuses some also. Space probe images on the internet are usually compressed as JPEGs, a process which adds rectilinear blocks of pixels visible when the image is over-enlarged. These are innocently reported as cultivated fields or city blocks.
Regrettably too, some of the people who look in images of Mars and see sphinxes and puma’s faces appear to be, to use a technical term, nuts (for example we are talking about people who hear coded messages about their theories in dialogue from The West Wing and men who tell the world that their child has been carried off in a balloon). I would love there to be relics of large scale alien engineering on Mars (and so would NASA, as it would guarantee a massive increase in their budget) but sadly there aren’t.
In the 1990s there was renewed robotic exploration of Mars, with six missions from NASA and one each from Russia and Japan. All of these failed though technical problems (or an embarrassing failure to convert metric to Imperial units in one case), apart from the Mars Global Surveyor and Mars Pathfinder but these were hugely successful and inspired further missions. Six more missions followed in the first decade of the 21st century (what about Beagle 2? Well, after it successfully landed it was trashed by a Decepticon…) These missions included the fantastic Mars Exploration Rovers Spirit and Opportunity, the Mars Reconnaissance Orbiter and Mars Express. These missions have revealed more of the planet’s history.
About 4 billion years ago Earth had a dense mainly carbon dioxide atmosphere, surface water and a molten core which generated a strong magnetic field. At that time Mars had all of these too, if life ever started on Mars, this was its big chance! Over the æons conditions on the two planets diverged. The magnetic field of Mars dwindled to nothing, leaving magnetised rocks as sole evidence of its existence. Loss of the magnetic field meant any Martian analogues of the van Allen Belts disappeared too, so the solar wind was free to blast the planet’s upper atmosphere, stripping away atoms (a process which continues to this day). The Martian atmosphere thinned and the shrinking seas became increasingly salty and acidic. Eventually liquid water could no longer exist on the surface (it is still plentiful as ice under the surface). Recently, it seems that water may exist on the surface but only as a transistory phenomena (see Summer’s Salty Tears). If Martian life had ever appeared it became extinct…or hid underground.
I have encountered several American space enthusiasts who have never heard of the Mars Express mission, which must say something about ESA’s publicity machine. In 2004 that worthy spacecraft detected the gas methane in the Martian atmosphere. “Oh hum” I hear you say, but this was really, really startling. Methane molecules are torn to pieces by UV light, and lacking an ozone layer, Mars receives rather a lot of this from the Sun. Any methane in the Martian atmosphere would fairly rapily disappear. Hence something on Mars is continuously adding thousands of tonnes of methane to the atmosphere every year to steadily replace it. Buried near the bottom, ESA’s press release offered the possibly than the methane had a biological origin (organisms on Earth produce copious quantities of this gas, memorably demonstrated in Mel Brook’s Blazing Saddles.
In other words, ESA was saying: THERE COULD BE LIFE ON MARS!!! Nobody noticed. By 2009 NASA had confirmed these observations (with Earth-based instruments) and announced the discovery of methane on Mars to the world in a press conference complete with marching bands and dancing girls (I made up the last bit). To be fair NASA had found two other interesting facts, the methane is released only from certain areas of the planet, areas that show evidence of ancient ground ice or flowing water, and the gaseous emissions are seasonal, occurring only in the warmer seasons. Food for thought, eh?
There are possible inorganic processes that could create methane but nobody had expected them to be happening on Mars. NASA’s forthcoming MAVEN mission will study the Red Planet’s atmosphere in exquisite detail, and perhaps throw some light on the mystery but we really need to send human explorers there to drill and dig, seeking out any Martians where ever they may be hiding (are you listening President Obama? Mr Hu Jintao? Elon Musk?)
When I started this Martian odyssey I promised an answer to the age-old question of whether our neighbour is a host to life. Based on what we now know of the planet’s history, the odd Viking experimental results and the anomalous methane emissions, in my opinion, it is a definite “maybe”!