Little green men or little green germs?
Many people would be satisfied in finding any extraterrestrial civilization, or any life at all, after 50 years of search of intelligent life forms outside the Earth. I decided to ask a microbiologist what microbiology has to offer to a person that is interested in this interstellar hunt for anything living.
Photo: Kaibara87 Flickr Creative Commons
50 years ago in April Frank Drake attempted for the first time ever to listen to radio communication of other intelligent life forms. He did this by pointing a radio telescope to outer space, towards a promising star systems, and that’s what some people have done ever since.
Nowadays one can partake in it through the SETI@home –project by allowing one’s own computer to analyse the data from several telescopes from around the world. SETI stands for Search for ExtraTerrestrial Intelligence. However, a large portion of life here on Earth (actually pretty much any life on Earth) doesn’t use radiowaves to communicate.
A science that is interested in questions concerning not only intelligent life but life altogether outside Earth is called astrobiology. In recent years interest towards astrobiology has grown, and astrobiology has grown from science fiction to a real science.
In search for life one shouldn’t concentrate on intelligence
The Finnish Astrobiology Network (FAN) has members from several areas of natural sciences. Naturally there are astronomers but also geologists and molecular biologists. I went to meet docent Kim Yrjälä, who is a member of this network and works at the University of Helsinki. He specialises in microbial ecology.
No intelligent life has succeeded in sending us a message in 50 years (or at least we haven’t gotten their message). So, you would think that looking for microbes from other planets would be a bit like looking for a really small needle in a really, really big haystack.
Yrjälä doesn’t agree with me entirely. Around 30 years ago there still was a solemn concensus about that bacteria needed a certain temperature, humidity, acidity etc. to be able to live. The conditions under which life might occur where very restricted.
New techniques open new possibilities
For the past 10 years plenty of research has been conducted on extremophile microbes such as bacteria that can survive in boiling water, sub-zero temperatures and other surroundings that were previously thought to be too hostile for microbes. Actually latest research has shown that, at least on Earth, there doesn’t seem to be any place that wouldn’t harbour some microbe population. Microbes that seem to be very adaptable and quite probably could also live outside Earth.
The 1970s and 1980s brought new techniques that allowed studying the genomes of microbes. This has considerably changed the microbiological research. According to Yrjälä any sample taken from nature contains mostly microbes that can’t be easily grown in laboratory.
Only a few per cent of microbes can easily be cultivated. With new techniques it isn’t necessary to cultivate microbes but instead a microbiologist can concentrate on only studying the genes. This has made studying extremophiles and actually even observing them a lot easier.
Microbiologists to the Mars?
So we have waited for a radio message for 50 years and heard nothing. On the other hand we know from our experiences on Earth that simpler life forms are abundant. Maybe Mars is filled with little green bacteria instead of little green men? But since we can’t see microbes from our radio telescope data, what do we do?
According to Yrjälä life always leaves traces of it even to the inorganic part of nature. With the experience from life on Earth we know what sort of compounds would implicate microbial life on other planets that would. So we might not want to pack a microbiologist and petri dishes to the next probe we send to Mars, but a chemistry laboratory instead.
Astrobiology is still a very new science. The possibility of life outside Earth is nowadays a relevant question and Yrjälä says that for example many students have shown interest in the subject recently. Basic courses on astrobiology have already been taught at the University of Helsinki. Since astrobiology requires by definition several sciences to cooperate it is proceeding slowly. On the other hand an astromicrobiologist’s work would include very interesting field trips. To be able to study extremophiles, one would have to travel to Hawaii, New Zealand and Iceland, for example.
Jan Jansson is a chemistry teacher that spends his little free time doing molecular gastronomic experiments.