60 | April• 2018
one-third of our gravity, less than one
per cent of our surface air pressure
and an average temperature below
inland Antarctica’s.
Yet it’s still our most Earth-like
planetary neighbour, topping the
space-travel bucket list ever since Neil
Armstrong’s one small lunar step in- Back then NASA intended land-
ing a crew on Mars by 1986, but the US
timeframe is now the 2030s.
So far, only robotic probes have
visited Mars. Around 50 have been
launched since 1960. Eight are still
operational: six in Mars orbit (three
US, two European, one Indian) and
two (US) roving the surface. he rover
Opportunityhas been sending back
data since 2004, but it’s an exception.
The high failure rate of unmanned
Mars missions – more than half
crashed, missed the target or other-
wise malfunctioned – highlights the
risk of sending people so far out.
local site, Arkaroola in South Aus-
tralia, has good examples, plus plenty
of Mars-like landscape for engineer-
ing trials and science projects.
“Fossilhotspringsareaveryim-
portant target on Mars,” Clarke says,
adding that studying Earth’s modern
hot springs is also important. “hey
contain extremophiles, organisms
that tolerate extreme temperatures,
acidity, extreme alkalinity and so on
- conditions we might ind on other
planets. Extremophiles are very inter-
esting to astrobiologists.”
Arkaroola even has mildly radio-
active hot springs hosting microbes
with radiation-tolerant genes – a
handy attribute for life on Mars,
where the atmosphere is too thin to
shield against cosmic rays.
Mars certainly has much to ofer an
extremophile – apart from radiation,
there’s a deadly (95 per cent carbon
dioxide) atmosphere, no liquid water,
Clarke and space journalist Anastasiya Stepanova conduct ield research; MarsPHOTOS: THE MARS SOCIETY; (MARS) ISTOCK