To see Mars or Venus close up, you don’t need billions of dollars or a job as a rocket cabin-crew member for one of the tech zillionaires diverting their taxes to spend more on space travel. Both deities are to be found resting contently, not in the heavens, but in Botticelli’s masterpiece Venus and Mars in Britain’s own National Gallery.
A post-coital Mars reclines, eyes closed, like Jacob Rees-Mogg during a parliamentary debate on Welsh farming. Venus looks on, serene in the knowledge that love conquers war.
In the classical world, fascination with the heavens was as strong as it is now. The Egyptian astronomer Ptolemy wrote about both Venus and Mars, although he thought the planets revolved around the Earth.
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Times have changed, with our knowledge powered by human curiosity. But it feels apt that in the space age, modern scientists revere the same two names that have long entranced us in the fields of ancient religion and renaissance art.
In 1962, in that famous speech, JFK articulated our wonder at outer space and pledged to put a man on the Moon before the decade’s end. “We mean to be a part of it… for the eyes of the world now look into space, to the moon and to the planets beyond.” He noted that if America’s Mariner spacecraft reached Venus, “we will have literally reached the stars before midnight tonight”.
Now, Venus – which we see as the evening star, the brightest object in the night sky after the moon – is set to be visited by us again. Nasa announced on Thursday 3 June that it is launching two robotic missions between 2028 and 2030 – its first to Venus in decades.
Earth’s closest planetary cousin might be named after the benign Roman goddess of love. But there’s nothing welcoming about the second rock from the Sun.
Nasa describes it as a “hot, hellish unforgiving world”. Above its foreboding landscape lies a thick, toxic atmosphere topped with clouds of sulphuric acid.
The abundance of carbon dioxide has caused a runaway greenhouse effect that burns the surface with temperatures as high as 471°C. Lead would melt. Even if you could survive the heat, the “air” on Venus is so dense that the atmospheric pressure would crush you.
As is often the case when Nasa is planning to spend big bucks (and seeking to justify it), intriguing but probably groundless claims regarding extraterrestrial life have conveniently emerged.
Last year, a team of researchers claimed to have detected traces of an organic gas in Venus’s atmosphere.
The presence of phosphine, which is produced by living organisms, raised the tantalising possibility that some strange life forms were eeking out a living above the hell planet’s sulphur dioxide clouds – though most scientists tutted with scepticism.
Still, Venus may once have harboured seas of water potentially suitable for life, before unknown forces triggered its extreme greenhouse effect, vaporising its oceans. The new missions may help uncover what led to the cataclysmic events.
Similarly, Mars, the red planet named after the hot-tempered god of war, is nothing like its classical namesake. It’s a cold and lifeless place, despite visions of alien civilisations by the US sci-fi writers Edgar Rice Burroughs and Ray Bradbury.
Their fantasies were quashed in 1976 when Nasa got its first close-up images after the arrival of the Viking 1 orbiter and probe. These revealed not lush canals, but a barren, rock-strewn world. The famed astronomer Carl Sagan was reportedly “never so depressed” in his life than at this news.
That hasn’t stopped many missions being to the planet since then at huge cost – including China’s Zhurong rover, which landed and began sending back pictures in May, joining Nasa’s Perseverance on the surface.
The US agency has ambitions to send humans to Mars (once they have reconquered the Moon by 2024). But getting there – and staying there – would be no holiday. The absence of gravity during the long voyages to other planets would weaken our muscles and bones.
Our skin would plump up, apparently, as fluid, unconstrained by gravity, returned to the face. But a short-term disappearance of wrinkles wouldn’t be much compensation for the destructive effects of cosmic radiation.
Experts have calculated that astronauts on the International Space Station receive about 1,000 times the average yearly dose of cosmic rays that you get at sea level on Earth, from the bullets of radiation flung out of dying stars. However, once you head further out to space, it’s estimated these radiation levels become 500,000 times greater.
And if the cosmic radiation doesn’t get you, it’ll probably be because the ultraviolet radiation bathing Mars surface, with no ozone layer to impede it, has fried you first.
Imaginative researchers writing in Earth Science Review last year had the solution. As neo-Martians, we could live in “lava tubes” – mile-long subterranean caves that would shield us from the cosmic radiation. But who’d want to travel 150 million miles to live in a giant underground car park?
In the more hospitable climate of Nasa’s Johnson Space Centre in Houston, Texas, Francis McCubbin, an astromaterials curator, collects lumps of material from the moon, the planets and passing asteroids. He thinks these will build up as we enter the “golden age” of space-sample retrieval.
Samples can tell astronomers if asteroids harbour organic matter that may have led to life on Earth, as well as reveal the spectrum of material found in the solar system.
Their value lies in their ability to answer questions that researchers haven’t yet thought to ask and their potential to bolster future scientific breakthroughs.
But rocks from Mars lose their lustre in a museum case. Perhaps the most exotic and thrilling aspects of planets, like the deities they’re named after, lie in our imagination, not the stone cold – or blisteringly hot – reality.
This Article firstly Publish on inews.co.uk