In Arthur C. Clarke first novel The Sands of Mars (1951 – Fig. 1), his central character, an author ‘still on the right side of forty-five’, had a best-seller in his youth, before humans reached Mars, called Martian Dust. We learn nothing about it except that it was ‘space opera’ (action-adventure), but the dust is back in the news. Later in The Sands of Mars, he survives a forced landing in a jet brought down by a dust storm. Arthur might have claimed some prophetic insight for that, but that when he sees the storm ahead in the sunset, he takes it for a mountain range until he remembers that ‘There are no mountains on Mars’ (Arthur’s italics) – a claim which he withdrew during the Mariner 9 mission of 1971, at a conference with Carl Sagan, Ray Bradbury and others, whose transcript was published as Mars and the Mind of Man (Harper & Row, 1973).
Percival Lowell’s best-selling books about Mars, and the fictional portrayals by Edgar Rice Burroughs and Ray Bradbury, had firmly established the public perception of Mars as a world which was older or had aged faster than Earth, heavily eroded and mostly desert. It had to be virtually flat to allow the network of canals which Lowell thought he saw (Fig. 2), carrying water from the polar caps to support remaining ‘oases’ of life, almost invariably selected for depiction by artists in the first half of the 20th century. Chesley Bonestell’s early depictions were similar, particularly for Willy Ley’s The Conquest of Space, contemporary in the UK with The Sands of Mars. His later artwork for The Exploration of Mars, by Willy Ley and Wernher von Braun (1956) was more cautious about the canals, but still showed the landscape as flat and eroded, as did his later versions for Mars by Robert S. Richardson (1964), a chapter of which was apparently omitted to make room for the first photographs by Mariner 4, published as an appendix.
As luck would have it, Mariner 4’s track of images across the Martian disc (Fig. 3), and the subsequent imagery of the equator and the south polar region by Mariners 6 & 7 (Fig. 4), all missed the more spectacular features and seemed to back up the idea that Mars had no landscape except for craters, which looked like the Moon’s, in black and white, at first glance. Shortly before the arrival of the Mariner 9 orbiter in 1971, the National Geographic Magazine had a major article about the Solar System, illustrated by the Czech artist Luděk Pešek, which captioned the aerial view of Mars as ‘a flat dull uninteresting landscape’ (Kenneth F. Weaver, ‘Voyage to the Planets’, August 1970 – Fig. 5).
When Mariner 9 reached Mars only the shadows of the giant volcanoes were visible through the storm (Fig. 6), and the probe spent its time photographing the moons Phobos and Deimos while waiting for the dust to clear. The Scottish spaceflight society ASTRA held an exhibition in Hamilton at that time, for which the Jet Propulsion Laboratory rushed us the first photographs of Mars from orbit, and then kept them coming as the dust settled and Mars proved to be far more dynamic than expected, patterned with giant volcanoes and chasms. The first thing to show through the dust was the volcanic caldera at the summit of Nix Olympica, the Snow of Olympus, as it was then known (Fig. 7), but soon to be renamed Olympus Mons.
It was fascinating to watch as the dust settled and the lava flows around the summit came into view, looking almost as if they were flowing downslope (Fig. 8), as the caption said on the back, but of course that was impossible… until the dust fully settled and Olympus Mons, as it now became, was revealed as the highest mountain in the Solar System, so large that it needed a mosaic to show it all (Fig. 9), The 10” x 8” photos from JPL arrived in bright yellow envelopes, so distinctive that I put the first one in the exhibition, below the photos (Fig. 10), and from then till the end of the mission, a phone-round to say that another had arrived was enough to ensure a good turn-out at the following Saturday’s meeting. There was very little coverage in the news at the time: in New Worlds for Old (1979), my chapter title ‘There Are What on Mars?’ captures the reaction of an ASTRA member who was away at the time, and came back to find us discussing a planet nothing like his mental picture of it.
Martian dust is extremely fine, and probably abrasive, which may be a problem for future settlers. While airborne it gathers particularly in deep craters, like the Hellas Basin in the southern hemisphere, which appeared to be a blank in the simultaneous Mariner 6 and 7 flybys of 1969. When Mars approaches its closest to the Sun the dust lifts off in the winds, absorbing solar energy and powering huge storms which engulf the planet. Because the Earth’s orbit is nearly circular and Mars’s is markedly elliptical, that means that global storms often occur when Mars is also nearest to the Earth, at 15-year intervals. As a result the close opposition of Mars in 1956 was a disappointment – there had been great hopes because it was the first since the 200-inch reflecting telescope on Mount Palomar was commissioned in 1948. For 1971, the year of the Mars 3 and Mariner 9 probes, see below. In 1986, the year NASA had intended to send people to Mars in the post-Apollo programme, there was no global storm. The particularly close opposition of 2003, the closest for 60,000 years, was also clear, and the Hubble Space Telescope obtained views which are still often used in illustration of the planet. 2018’s storm was the worst since 1971 – see below. And 2034 awaits.
The Soviet Mars 3 in December landed on the rim of Hellas in December 1971, probably the most dangerous place on the planet at the time, and lasted just 30 seconds, in which it managed to return part of a single blank image. The Viking 1 and 2 landers in 1976 were nuclear-isotope-powered and not affected by dust, but the Pathfinder lander and its Sojourner rover were solar powered and lasted only 60 days after landing in 1977. A study was made of the build-up of dust from their solar panels as they gradually lost power. Sojourner is visited by Matt Damon in The Martian because he needs its radio to regain contact with Earth, after he’s stranded by a dust storm much more violent than any actually seen so far. Just how rough they can be is not entirely certain, despite the much-used quotation, ‘The winds of Mars might buffet a man unmercifully without his being aware of it’. Among those first photos from JPL there were some of eddies near the south polar cap (Fig. 11), and across the top of Olympus Mons, suggesting windspeeds of 2-400 mph. Subsequent discussions that led to my Man and the Planets (1983) took such conditions during storms to be typical – “Give us back the old placid Mars!” was a frequent outcry.
We produced conceptual drawings of heavily armoured conical landers, with return vehicles protected inside them (Fig. 12). They did at least seem to answer one mystery of 2001, A Space Odyssey: when the Moonship lands in the crater Clavius, a huge petalled dome opens with the landing pad in the centre (Fig. 13), on which the ship then descends on an elevator column, very tall and thin in lunar gravity.
But it’s also red-lit, which by the conventions of the film should mean it’s in vacuum (compare the sequence later where Bowman re-enters the Discovery through an emergency airlock.) So what is the function of the dome? It looks as if it’s been erected to protect from Martian dust-storms, rather than anything the Moon might throw at it. But during the years of its survival on the Martian surface, the nuclear-powered Viking 1 survived at least one planet-wide dust storm, noting no change in surface winds and only a diminution of overhead sunlight.
When the Spirit and Opportunity landers set down on opposite sides of Mars in 2004, neither was expected to last any longer than Sojourner and sure enough, dust began to build up on them. But suddenly they were clear again, and images from orbit showed the trails of the ‘dust-devils’ which brushing the dust off them (Fig. 14). (Sydney Jordan had correctly predicted those in his 1954 story ‘The Martian Invasion’, in his Jeff Hawke strip for the Daily Express.) In the event, Spirit lasted until 2010, when its wheels became trapped in soft dust and it couldn’t turn to face the Sun, to recharge its batteries for the winter. Opportunity lasted amazingly till 2018, visiting several craters before making a much longer traverse to Endeavour crater, exploring part of its rim, and it was about to descend a river valley into the crater when a planet-wide dust storm plunged it into darkness for too long. In the end, dust put both of them out of action, but in different ways from Sojourner’s.
The Phoenix lander of 2008, n the far north of Mars, didn’t last long enough into the winter for dust build-up to be a problem. In its short but successful time on the surface it didn’t need cleaning, although dust-devils were seen and even filmed going past it (Fig. 16). Later images from orbit showed that after it lost contact the solar panels had snapped off, due to a build-up of dust or frost (probably both) and been covered by dust on the ground (Fig. 17).
When it came to the Insight mission, which landed in 2019, it became clear that this time Mars would be less obliging, Dust started accumulating on the solar panels from the outset, and no dust devils came along to clear them. Apparently it was in a clear zone on Mars where they were absent, or at least less frequent. An improvised attempt at ‘sand-blasting’ by dropping sand on top of the lander shifted some dust, but not nearly enough. It became apparent that Insight had not only failed to drill down into the crust, which proved highly resistant, but its lifetime as a weather and geological station would be severely cut short, failing altogether in December 2022 (Figs. 18-20).
By April 2024, images from orbit showed the inert spacecraft rapidly being covered by dust (Fig. 21) – much faster than (for instance) Britain’s Beagle 2 lander, which was found in 2015, 11 years after its near-success, with at least two of its panels still recognisably open (Fig. 22). Even Russia’s Mars 3 lander of 1971 has provisionally been identified. The implication that there’s something different about the dust in Elysium, where Insight landed, is being investigated.
Photographs from Mars orbit show clearly visible trails from dust devils (Fig. 23), some of them at least very large, and columns of dust rising miles above the surface in some cases (Fig. 24), which imply a great deal of internal energy and probably lightning and other electrical phenomena. Similar water-fed columns on Jupiter can reach 50 miles in height, with very intense lighting, ten times anything seen on Earth. So although the storm which almost overturns the lander in The Martian is probably exaggerated, I wouldn’t take a bet on it just yet.
Martian settlements will have to be built mostly underground in any case, barring major developments in radiation shielding. In the absence of a planetary magnetic field, the surface is exposed to solar particle storms – early in the 2000 film Red Planet the spaceship is subjected to a gamma-ray storm (of all things, since gamma rays aren’t particles and can’t be focussed by solar magnetic fields) in which the tracks are not only visible in air, but do considerable damage to the ship’s wiring for no apparent reason. But streams of protons from Coronal Mass Ejections are focussed and highly dangerous, and heavier nuclei within them still more so. During Apollo 16 there was one such event which did not hit the Moon, and the astronauts would not have survived it if it had. Cumulative exposure to high-mass, high-energy galactic cosmic rays has even worse effects on central nervous tissue, and it’s calculated that a minimum-energy mission to Mars and back would give astronauts aboard a lifetime dosage, forcing retirement before they lost enough brain cells for noticeable effects. (Warning to critics: I have been accused before of making this up, and I have all the references to hand if needed.)
Every so often the media rediscover this problem, and a rash of articles appears saying that it proves Elon Musk’s plans to establish settlements on Mars are impossible. (There’s another one in progress at the moment.) But as Graham Dale of the Scottish branch of the Mars Society pointed out, in a discussion project called ‘Building the Martian Nation’, the situation on Mars is different. To begin with, the mass of the planet below cuts the radiation exposure in half right away (I made the same point about a mission to an asteroid in Incoming Asteroid!, 2013). Building the settlement beside a crater wall would halve it again – our choice was a lava-flooded crater on Lunae Planum which we called ‘Glesgae Sinus’ – not to be confused with any condition aggravated by passive smoking (Fig. 25).
Although Mars has no overall magnetic field, it used to have, shown by magnetic banding in strata south of Valles Marineris, detected by ESA’s Mars Express. There are also localised, residual magnetic fields, some at least of them over impact features, intense enough to generate local aurorae (Fig. 26); and over the north polar hood during northern hemisphere spring, there’s enough oxygen from water molecules, disassociated by solar ultraviolet, to give significant protection and perhaps even to form a temporary ozone layer. So the Martian surface is not necessarily the death-trap that’s currently being portrayed. On the other hand, on May 20th this year the Curiosity rover recorded a solar radiation storm of such intensity that the particles are visible, as streaks and spots, in the images from the electronic cameras (Fig. 27).
That’s a situation where the only safe place is underground, and that’s something which SF writers foresaw long since. Sandi Cayless of Bridge of Allan has written three novels following the students and graduates of the ‘Sub Martis’ university of an underground Mars culture (Fig. 28). The late John Brunner portrayed one much earlier in ‘Born Under Mars’ (1967 – Fig. 29), one of the interesting aspects being the return of heraldry. In mediaeval times, that not only portrayed one’s ancestry and showed your troops whom to follow in battle; it also demonstrated, even among illiterate knights (as many of them were) whose siblings and offspring you could court and marry without breaking the laws against consanguinity. In the relatively small population of a Martian settlement, John reckoned coats of arms could save a lot of time in forming relationships, and in fending off predatory would-be in-laws – a problem and a solution to which NASA and Elon Musk may not yet have given much thought.
