By Matthew Knight for CNN
Adjust font size:
(CNN) -- When, after an eight-month voyage, NASA's Mariner 4 spacecraft beamed back the first images of Mars in 1965 -- to score a victory over Russia's Mars 1 in the Cold War space-race -- it changed the way scientists thought about the Red Planet.
The pictures revealed a battered and barren landscape, similar to that of the moon, which was in direct contrast to the long-held theories that Mars supported vegetation first put forward by French astronomer Emmanuel Liais in 1860.
Fueled by the fantasies and fears of science fiction writers -- most notably H. G. Wells' "The War of the Worlds" -- the paranoid notion of the invasion of Earth by Martians has been reversed as a succession of missions throughout the latter half of the 20th Century has allowed NASA scientists to better understand the make-up of Mars and publish evermore astonishing photographs of the Mars landscape.
Although there have been many critics of the Mar Missions who cite the expense and its failure rate -- only 18 out of 37 spacecraft from all countries have succeeded -- the so-called "Mars Curse" or the "Galactic Ghoul" -- a fanciful idea that a space monster eats Mars probes -- has yet to affect the more recent efforts of NASA scientists.
The Mars Global Surveyor (MGS) was launched in November 1996 and began orbiting a year later.
It has operated longer than any other spacecraft sent to Mars returning more information than all previous missions put together.
Until recently -- November 2, 2006 -- when scientists lost contact with it, the MGS has been mapping the planet and scouring the surface for potential landing sites.
Undoubtedly its greatest find has been the recent re-mapping of a gully site first photographed in 2001.
This reveals "bright new deposits" NASA said, "which gives the strongest evidence to date that water still flows occasionally on the surface of planet."
Inevitably scientists are excited by this discovery as it increases the chances of there being life on Mars.
The Mars Pathfinder launched a month after the MGS and upon landing on the surface of Mars deployed the Sojourner rover -- a robotic exploration vehicle -- which conducted experiments and paved the way for the most recent rovers -- Spirit and Opportunity -- launched in 2003 to carry out more complex tasks and maneuvers and continue to take the highest ever resolution photos of another planet.
Measuring 65cm long, 48cm wide and 30cm tall, the six-wheeled rovers resemble remote-control toy cars apart from their rather sluggish top speed of 50mm per second.
Both Spirit and Opportunity continue their lonely roam around the planet and have far exceeded their projected life spans of 90 days living well over one Mars year of 670 days. A complete contrast to the first successful landing by Russia's Mars 3 Rover in 1971 which lasted barely 20 seconds.
In August 2007 NASA launch the Phoenix mission which hopes to study the geological history of water and search for evidence of a habitable zone beneath the surface.
The observations and findings which are being recorded now pave the way for a manned Mars exploration which will surely happen later in the 21st Century.
An aerial view of the Martian landscape
Quick Job Search