The Red Planet
Mars: stimulating science and inspiring imagination
Since ancient times, Mars has captured the imagination of humankind, sparking an interest in scientists and artists. Over a period spanning two millennia Europeans have made many important observations of this Red Planet.
The association of Mars with life was strengthened in the 19th century when the Italian astronomer Giovanni Schiaparelli observed bright and dark straight-line features that he called "canali". This term was translated into English as "canal", instead of "channel", with the associated connotation of a manmade construction.
Magnificent images of the Martian surface from ESA's Mars Express.
Credit: ESA/DLR/FU (G. Neukum)
For a long time, it was popularly believed that these canals had been built by intelligent beings to form a huge irrigation network on the Red Planet. This aroused great interest even beyond the world of science inspiring visionaries, writers and philosophers: the myth of the Martians was born.
During the early part of the 20th century, the canal controversy ended when better telescopes allowed scientists a clearer view of the planet's surface. Later that century the start of the space age brought about a change in how the search for extraterrestrial life was carried out.
Scientists no longer look for intelligent beings, but for evidence for the presence of water - an essential element for the formation of life - either on the surface or hidden underground.
A new science: exobiology
In the mid 20th century, American geneticist Joshua Lederberg, Nobel Prize winner in Medicine, coined the word "exobiology" to describe the study of the existence of life outside the Earth and to outline the risk of bio-contamination related to space flights that might, in the future, contaminate and ruin bacterial ecosystems in outer space and on other planets.
Exobiology, also referred to as bio-astronomy or astrobiology, tries to answer the questions regarding the origin, evolution and distribution of life.
It wasn't until the second half of the 20th century that exobiology was raised to the rank of a science. This came about mainly as a result of the development of space technology and scientific programmes within the space agencies.
The goal of exobiologists became to find signs of primitive life, and Mars remained the target planet. According to current scientific knowledge about the possible development of life on Earth, the Red Planet could have (or had in the past) the environmental conditions (liquid water and moderate temperatures) capable of supporting complex organic molecules and possibly self-regenerated organisms.