A Pale Blue Dot..

One of the biggest achievement of mankind is , no doubt, the exploration of space. The starry sky with its shiny moon, moving planets and thousands of "fixed" stars , has always been a source of wonderment for man.

For one, these mysterious points of light where heavenly gods, for the other they were signs of God who could be read if studied well enough. For that, it does not come as a suprize to us, that for thousands of year Astrology has gone hand in hand with Astronomy.

These beliefs did not change very much, until the invention of the telescope. Suddenly, the moon was not a shining disk but a world with strange but "earth-like" landscape and the planets, which for thousands of years have been mysterious moving lightpoints, became small disks.

Suddenly, the fact that the moon and these planets were not points of light but "earth-like" globes gave birth to ideas that would nobody would have dreamed of before.

One famous example is the english philosopher John Wilkins, who in 1638 published a work named "The Discovery of a World in the Moon" in which he put his rather "radical" ideas and beliefs on space travel and space habitation.

Wilkins believed that the Moon is a habitable planet and he predicted that one day travel to the Moon will be possible. Wilkins was not the first to come up with this suggestion but it is typical of the way that he thought, allowing his mind to roam through ideas which others would have found too unconventional to consider. [1]

One chapter of the book bears the title, "That 'tis possible for some of our posterity to find out a conveyance to this other world; and, if there be inhabitants there, to have commerce with them." It is thus that the right reverend philosopher reasons:--

"If it be here inquired what means there may be conjectured for our ascending beyond the sphere of the earth's mathematical vigour, I answer.--1. 'Tis not possible that a man may be able to fly by the application of wings to his own body, as angels are pictured, as Mercury and Daedalus are feigned, and as hath been attempted by divers, particularly by a Turk in Constantinople, a Busbequius relates. 2. If there be such a great duck in Madagascar as Marcus Polus, the Venetian, mentions, the feathers of whose wings are twelve feet long, which can scoop up a horse and his rider, or an elephant, as our kites do a mouse; why, then, 'Tis but teaching one of these to carry a man, and he may ride up thither, as Ganymede does upon an eagle. 3. Or if neither of these ways will serve yet I do seriously, and upon good grounds, affirm it is possible to make a flying chariot, in which a man may sit and give such a motion to it as shall convey him through the air. And this, perhaps, might be made large enough to carry divers men at the same time, together with food for their viaticum, and commodities for traffic. It is not the bigness of anything in this kind that can hinder its motion if the motive faculty be answerable "hereunto. We see that; great ship swims as well as a small cork, and an eagle flies in the air as well as a little gnat. This engine may be contrived from the same principles by which Archytas made a wooden dove, and Regiomontanus a wooden eagle. I conceive it were no difficult matter (if a man had leisure) to show more particularly the means of composing it. The perfecting of such an invention would be of such excellent use that it were enough, not only to make a man famous but the age wherein he lives. For, besides the strange discoveries that it might occasion in this other world, it would be also of inconceivable advantage for travelling, above any other conveyance that is now in use. So that, notwithstanding all these seeming impossibilities, it is likely enough that there may be a means invented of journeying to the moon; and how happy shall they be that are first successful in this attempt!" [2]

A few centuries after Wilkins, Jules Verne, the world famous novelist would write a story about travelling to the moon. This time it was not a flying chariot with wooden wings like Wilkins imagined it, but a large metal cannon, that would shoot people to the moon. An idea that clearly shows traces of the industrial revolution. Wood was replaced by metal and wings by a big canon.

Bigger, faster, heavier...

Not long after Jules Vernes novel , famous scientists like Tchiolkovski, Goddard and Von Braun made major contributions to the science of rockets and soon rockets that could carry people and robots into space became a fact.

For over 50 years years now, spacecraft have been travelling through space to explore new worlds. Starting from the very first artificial satellite, the sputnik, to the "New Horizons" spacecraft being prepared for launch this month and which was developed for a 10 year long journey to Pluto, the only planet never visited by a spacecraft.

Strange enough, the biggest achievement of Space exploration is not very recent but going on for over 30 years now. The Voyager 1 and 2 spacecraft, launched in the late seventies are still the only spacecraft to leave our solar system. Thanks to their succesful design and nuclear batteries, the Voyager spacecraft keep sending us information, even long after leaving our solar system.

Perhaps, the most famous "public" symbol for the voyager space mission is a picture called "The Pale Blue Dot". This picture, which is also the title of a famous book written by Carl Sagan, is no doubt the most special picture ever made.

This picture was taken in 1990 , 17 years after the launch, at the moment that the Voyager spacecraft was just about to leave our solar system at a distance of 6.4 billion km from earth when the spacecraft was cruising at a speed of 40 km/s.

Carl Cagan, working at NASA at that time, suggested to turnback the cameras of the spacecraft to make a final "family" picture, before it would start on its solitary journey into the vast darkness of space.

When the picture was transmitted back to Earth, the picture showed a minute pale blue dot in one of the coloured streaks of light. That dot, smaller than a pixel, was nothing else than our planet, our cradle, our home.

A picture that, on one hand, shows the greatest achievements of mankind, but on the other hand shows how small , little and vunerable we are.

A strange idea to see that our the world, which is so special and important to us, is nothing more than a "pale blue dot"..



References:

[1] http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Wilkins.html
[2] F. Marion, Wonderful Balloon Ascents: Or, the Conquest of the Skies, Chapter 2,
http://www.worldwideschool.org/