Astrobiology is the perfect interdisciplinary name for the crossroads of sciences that collectively study life with a cosmic perspective. How did life arise and evolve on our planet? Does life co-evolve on Earth? Is there life elsewhere in the universe? What does it tell us about the future of intelligent life on Earth?
Astrobiology asks the above series of important questions requiring an interdisciplinary approach. The uniqueness of astrobiology is that it has a cosmic perspective of life in the universe as a vector in biology, microbiology, astronomy, geology, chemistry, astrophysics and the social sciences (the latter because some questions are at least in part philosophical, such as “what is life?”, “how do we define intelligence?”, “how do we ensure Earth remains habitable?” and “will we be able to travel to other planets in the solar system and beyond, given our dependence on Earth’s specific biosphere?”.
While the question (and its related questions) “Are we alone among the stars?” has been pondered for thousands of years, astrobiology is relatively new, requiring advances in astronomy and the space age to realise that it is a distinctly interdisciplinary field and for empirical experiments to begin. In an article in the French Journal La Nature in 1935, the term ‘astrobiology’ was first mentioned by a Russian of Polish origin, Ari Sternfeld, to describe the interdisciplinary nature of the subject. However, Lafleur’s 1941 article for the Astronomical Society of the Pacific is more widely regarded as the first mention of astrobiology that aligns with its use today.
How did astrobiology get started?
Nobel Laureate and biologist Joshua Lederberg kickstarted astrobiology at the dawn of the space age, although he called it ‘exobiology’. He was a visiting Fulbright scholar at the University of Melbourne in 1957 and saw Sputnik 1 from Australia shortly after its launch in October of that year. He instantly became concerned about microbes from Earth infecting other worlds or extraterrestrial microbes being brought to Earth, realising the possibility of life elsewhere – even in our neighbourhood of the solar system. Lederberg won the Nobel Prize for discovering that microbes could mate and exchange DNA.
NASA took Lederberg’s seriously from its inception in 1958, taking measures to prevent possible microbes from the moon arriving on Earth with the return of the astronauts who walked on the Moon between 1969 and 1972. Planetary protection remains a keystone of NASA’s missions to other worlds in the solar system – Mars, Jupiter, Saturn and the moons of those planets visited by its spacecraft.
Lederberg’s passion for exobiology ensured that looking for life elsewhere would become an inseparable part of the NASA space program and receive funding. NASA funded the Instrumental Research Laboratory from 1961 with Lederberg as its Director at Stanford University Medical School. He played a major part in the instrumentation for the Viking landers in 1976, the mission for which was to look for microbial life on Mars.
The Vikings’ mission was inconclusive and ended a year later with the perception that Mars was a dead planet. There were no more visits to the surface of Mars for several decades. That changed in 1996 with the NASA news of possible evidence of past life in a meteorite from Mars, ALH84001. Although that was dismissed too, the debate prompted new interest in exploring Mars and beyond. With better instrumentation, we now know Mars was a habitable planet. The latest NASA Mars rover Perseverance is now looking for evidence of past life on Mars – the first life-seeking mission since the Viking landers.