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Astronomers get close-up view of Mars
Mars is getting ready for its close-up, with the Red Planet set to
come as near to Earth this month as it has in nearly 60,000 years.
August is proving an unforgettable month for amateur astronomers as
they turn their gaze on Mars, which is at its closest to earth since
Neanderthals walked our planet.
Belgian astronomer Jean Meeus says the Red Planet will be 55.76
million kilometres from earth on August 27. Proximity of this kind
last occurred nearly 60,000 years ago.
The earth - the third rock from the sun - has the inside track over
Mars, the fourth planet, as they orbit the sun.
Earth takes a nippy 365 days to make a circuit, whereas Mars takes 687
earth days because it is further out.
This celestial ballet means earth whizzes past Mars once every 26
months or so. However, the two planets take a slightly egg-shaped path
around the sun and this factor mainly determines just how close the
flyby will be.
In fact, astronomers say the next time the two planets will be closer
than in 2003 will be in the distant future - in 2287.
On August 27, Mars will shine red and orange, not of course as big as
the moon or anything near its size in the sky but certainly as bright
as Jupiter, the regal giant of our solar system, ever gets. Skygazers
have been thirsting for the moment.
"The Red Planet will present a large enough disk for backyard
astronomers with good-sized telescopes to discern some of the planet's
features, such as the polar ice cap, dark surface features and perhaps
even storm clouds," the specialist website space.com says.
Divine body
Mars has always cast a spell on earth, either as a divine body, a
fictionalised source of invasion or as earth's verdant twin.
Dreamers see it as humans' first colony in space, a stepping stone to
a wider conquest of the solar system and perhaps the galaxy beyond.
"The earth is the cradle of humanity but we cannot live forever in a
cradle," the Russian physicist Konstantin Tsiolkovsky, an early
visionary of interplanetary travel, wrote in 1911.
No fewer than four new probes - two US, one European and one Japanese
- are hurtling towards Mars, with their main goal to resolve the great
enigma: does life, or the potential for it, exist on earth's
neighbour?
The first of these rendezvous, by Europe's Mars Express orbiter and
the Beagle-2 lander it is carrying, is scheduled for December 25.
But even if these missions confirm that Mars holds water - the
essential substance for making it a staging post for humanity - many,
many years are likely to pass before a human sets a footprint in its
dusty surface.
In 1952, the German scientist Wernher von Braun, father of the Nazis'
V-2 rocket but also a pioneer of the US space program, sketched his
own ideas for what it would take to get humans to Mars.
The big technical challenge then, as now, is that our chemical
rockets, designed for orbital flight or at most a trip to the moon,
are just too slow, cramped and fuel-inefficient for a trip spanning
tens of millions of kilometres.
At such speeds, the first astronauts to Mars would have to spend about
six months just to get there; a year or so there to carry out
experiments, prepare for the return trip and wait for the planetary
alignment to close once more; and another six months to get back.
Call it a round trip of two-and-a-half years: an odyssey that would
place extraordinary stresses on the crew's mental and physical health,
their supplies and equipment.
"The conventional propulsion techniques which we have mastered today
mean that we have to take the path of economy," says Richard Heidmann,
a former executive with the French rocket engine maker Snecma and
president of Planete Mars, the French branch of the Mars Society,
which promotes interest in our ochre neighbour.
"In other words, we have to take trajectories which do not use up lots
of fuel but they are slow."
Until a faster technology emerges - NASA, for instance, is dusting off
old ideas for nuclear propulsion - Mars will remain a twinkling but
distant lure.
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