The mystery of whether there is life on Mars has captivated imaginations for generations. The latest mission there could finally provide certainty to astronomers and stargazers alike.
Over the centuries, astronomers thought the dark lines on its surface might be canals, built by an ancient civilisation for carrying water.
The Mariner missions to Mars in the 1960s and 1970s ended these romantic notions by revealing them to be impact craters similar to those found on the Moon.
The Viking landers in 1976 served to reignite the hope that life may have existed by revealing the planet to have almost certainly once had an abundance of water, which is essential for life.
A few weeks ago, the Mars Express space probe was launched from Baikonur in Kazakhstan to begin its six-month journey.
Mars Express carries on board a 60kg capsule called Beagle 2 which is named after HMS Beagle, on which Charles Darwin travelled while developing his evolutionary theory.
Beagle 2 will be released by Mars Express and will enter the Martian atmosphere on Christmas day of this year. Once landing on the surface of Mars, its many onboard instruments will begin the complex task of gathering information from the surface, such as rock composition and atmospheric investigations.
Scientists hope the Mars Express will help to answer questions raised by previous missions such as: if Mars was once covered by vast oceans, how did it evolve to the desert it is today? It will also try to finally answer the question of whether life once existed on Mars and even the possibility that life may still be present.
Technology boost
The Mars Express is the first European Space Agency (ESA) probe to be sent to another planet.
While witnessing the launch from Baikonur, David Southwood, ESA’s Director of Science, said: “Europe is on its way to Mars to state its claim in the most detailed and complete exploration ever done of the Red Planet. We can be very proud of this and the speed with which we have achieved this goal”.
The space probe weighs 1120kg and has been manoeuvred into a Mars-bound trajectory by its on-board propulsion and steering system. It will travel away from the Earth with a relative speed of over 3km/s and cover 400 million kilometres in six months.
In September, it is expected to perform a mid-journey correction to its trajectory after which the probe will be largely deactivated until late November.
On December 20, Beagle 2 will be released into a collision course with Mars decelerated by two parachutes and using three airbags to soften its landing.
Beagle 2 is powered by solar panels enabling its instruments, comprising of: two cameras, two spectrometers and a microscope – which are located at the end of a robot arm – to begin work. It is hoped rock samples can be collected and dated accurately.
Meanwhile, the Mars Express will be in orbit around the planet also carrying out a detailed investigation of the planet. A very high resolution stereo camera (HRSC) is hoped to send back to Earth photographs of the Red Planet’s surface. The Mars Express will then relay all information back to Earth.
First return
So far, all of the missions to Mars have been unmanned and one-way trips.
Return trips throw up issues concerning the amount of fuel that would have to be carried in order to get back. Suggestions, by Dr Robert Zubrin, have been made to transport some of the ingredients required for fuel to Mars and then use the Carbon Dioxide in the Martian atmosphere to manufacture fuel on the Martian surface. However, in an age that favours “microtechnology” such a grand and expensive scheme is unlikely to be seriously considered for some years.
There is much discussion in this new millennium of sending a human crew to Mars. Although the Martian climate is harsh – with extremely low atmospheric pressure and sub-zero temperatures – the only obstacles to establishing a human presence on Mars are purely engineering problems.
Should a human crew ever travel to Mars it is likely the aim of the mission will be to establish a permanent presence, leaving behind them an infrastructure that can be used by their successors.
So even if the Mars Express conclusively rules out that life exists on Mars at present or in the past, it remains very possible life will exist there in future.
