Phoenix Lander and the 'Canals' of Mars
On May 25 the Phoenix Lander will arrive at its destination near the Martian North Pole. It's hunting for that most precious of materials, water. So it's a pity that it went during the one era in time when we don't believe there are any canals.
Unlike the roving Spirit and Opportunity, the Phoenix won't be able to move around. Instead, its final destination was chosen before it ever left Earth, and over its entire four hundred million mile journey the lander has been aiming at one precise point - a feat which requires some careful calculation and navigation. While the Rovers were designed as lightweight scouts to get out and about, the immobile Phoenix lander acts more like a survey station. The heavier design means it can carry many more tools, including a robotic arm which will dig over a meter into the Martian soil (where there is believed to be an eighty per cent chance of finding life-giving H20). Other heavy duty science equipment include a mass spectrometer, an atomic force microscope, incredibly sensitive cameras for on-site analysis, and large solar panels to power the systems.
One drawback of landing is obvious: you mess up the one spot on the entire planet you're going to looking at by dropping three hundred and fifty kilograms of spacecraft on it. In fact, if you don't want your probe's examination of the surface to be extremely brief and alarmingly dynamic, you have to fire landing thrusters into that ground as well (Phoenix will be traveling over twenty thousand kilometers an hour on its way to Mars, slightly faster than ideal for landing!). To counter this the Phoenix is equipped to take high resolution images of the surface just before landing. Also, the landing thrusters use a very specific fuel mixture which scientists can screen out of any results (because unless is significantly more flammable than heretofore believed, there isn't any hydrazine in the soil). Finally, the most interesting samples to be gained will be those excavated from under the surface, where they should remain free of thruster contamination.
The idea for water on is not new. In 1895, Boston-born Preston Lowell published "Mars", a book which documented his telescopic observations of the red planet - including a detailed account of the canals the inhabitants had built. While these have since been written off as artifacts of the limitations of telescopes at the time, and Mars remains disappointingly inhabitant-free, the idea that there could be water - and life! - on one of our nearest neighbors has never left the imagination. Perhaps because we know it's our next stop if we ever get out into the solar system (Venus is slightly closer, but the conditions are a fairly good approximation of hell). Perhaps its because of all the movies telling us that little men from there were going to blow us up, before being destroyed by something trivial like the common cold, water, or even more unlikely, Mel Gibson.
And perhaps if there aren't any canals, we'll just go and build them ourselves. The renewed interest in Martian exploration raises hopes of human exploration in the future, maybe even the incredible dream of terraforming. A great deal of research has been done on these idea - and one key point is that we'd have to start moving the water from the poles, where we believe it's hiding as ice under the surface (where Phoenix will hopefully find it). World-famous scientist author Carl Sagan believed the answer was obvious - if the canals weren't there, we would just have to make them. Maybe Mr Lowell was misled by optical artifacts - or maybe he just got a glimpse of the future.
Posted by Luke McKinney.
A few years ago, someone imaged Mars with a CCD camera and about a 20" scope, and got canals. That suggests that it wasn't an image of Lowell's retina, but rather was an artifact of that sized scope, and perhaps seeing through our atmosphere.
I still expect we'll find life on Mars. It will likely be related to life on Earth, due to natural transfer of material. It will be interesting scientifically, but won't answer the origin of life questions. Then the question is, do we have the right to disturb it?
Once winter sets in, the expanding cap should crush Phoenix to a pulp. It is not expected to rise from the ashes. It must be at least a little tought to send your life's work to it's death.
Posted by: Stephen | April 28, 2008 at 08:41 AM
Did you mean Percival Lowell?
Posted by: sharon | April 28, 2008 at 12:40 PM