Down here in southern Spain, the views of Mars as it made its closest and brightest approach in 15 years on 27th July, were spectacular, and as I write this, it still dominates the southern sky, shining at magnitude -2.1 in the constellation of Capricornus.
I’m observing with my old 105mm Vixen refractor, but although viewing conditions here are excellent, I can’t see much detail as there has been a planet engulfing dust storm covering most of the planet since May, nonetheless it’s still worth watching as I get a much better view here than from England, as I’m 30 degrees further south, so Mars is much higher in the night sky.
In the years before spacecraft probed the Martian surface, observers put eyeball to eyepiece and reached some outlandish conclusions. Some saw vast areas of vegetation, others using telescopes glimpsed lines seemingly etched across Mars’ shimmering ochre disk, igniting controversy over the existence of extraterrestrial life. In 1666 Giovanni Cassini spotted the planets’ north and south polar ice caps. In 1784 Sir William Herschel determined that Mars had an axial tilt similar to Earth’s, thus, it had seasons. It was also seen to have an atmosphere leading to Herschel speculating “its inhabitants probably enjoy a situation in many respects similar to ours.”
In the centuries that followed maps were produced of surface features. The Italian astronomer Schiaparelli sketched lines and markings that he thought he could see through his 220mm reflector and called them canali meaning channels or grooves. This was completely mistranslated in English into ‘canals’ suggesting an artificial construct, and thus furthering speculation as to the existence of Martians!
Wealthy Bostonian and astronomer Percival Lowell mapped in great detail this planet girdling canal system and deduced that Mars was a dying planet, whose inhabitants were trying to stave off the ever-encroaching desert. It was this doomsday scenario that lead to books such as War of the Worlds in 1898.
Up until 1964 Mars was still being promoted by authors, artists, filmmakers as earthlike, with an almost breathable thin atmosphere, canals, water and edible vegetation. Since the first visit by Mariner 4 in 1965 we now know that Mars is a very beautiful, desolate place, a barren, hostile world, yet more complex and fascinating than ever.
It has been visited by many missions since then and this period really can be called ‘The Reign of the Robots’: robotic autonomous craft. Some are Landers such as Opportunity and its much bigger cousin Curiosity both roving around analysing soil, geology and of course looking for evidence of water. Up above, in orbit are Mars Express, Mars Reconnaissance Orbiter, Mars Odyssey, Maven, and Mangalyaan all studying a variety of disciplines from atmospherics, pressure, radiation, climate, minerology, planetary structure etc. There are many more missions in the pipeline for the 2020/30 decade all leading up to the possibility of a manned mission and ultimately a colony on Mars.
Elon Musk and his company Space X have an ambitious plan to be the first to the Red planet, to establish a secure base, then a viable colony and then further down the line, terraforming the planet! The latest discovery is very exciting as ESA’s Mars Express has used signals bounced through underground layers of ice to find evidence of a body of water buried below the south polar ice cap, using the Mars Advanced Radar for Subsurface and Ionosphere Sounding Instrument, MARSIS.
Due to Mars’s extreme temperature range from 30C to -140C at the poles (Mean Temp. -63C), it is almost certain to have a very high salinity which acts like an antifreeze. A final point concerning the colonization of Mars. Science fiction writers have long featured ‘terraforming’, the process of creating an earthlike or habitable planet in their stories. Scientists themselves have proposed terraforming to enable long term colonization of Mars. A solution common to both groups is to release carbon dioxide gas trapped in the Martian poles, to thicken the atmosphere as a blanket to warm the planet. Unfortunately there simply isn’t enough CO2 left to achieve this.
Elon Musk has proposed exploding multiple thermonuclear bombs at each pole to melt the ice caps and release the carbon dioxide gas…ahem, I think that is a bad, very bad idea. Terraforming the inhospitable Martian environment into a place people could explore without life support is not possible without technology well beyond today’s capabilities.