Three days of talks and discussion are over and I’m on the train back home so its time for a recap.
Astrobiology is a very diverse subject but can pretty much be summarised in three questions:
- Where do we come from?
- Where do we go?
- Are we alone?
I guess it’s quite easy to see how some subjects like the search for extraterrestrial intelligence (SETI) easily fit into this. But there is so much more to it.
The conference kicked off with a session about Mars, which is in the public limelight for some years now. The talks covered some of the latest discoveries by Curiosity as well as assessing the habitability of Mars and the search for ExoMars landing sites, which wants to search for signs of life. But Mars research can also be done on Earth by analyzing Mars analogues in the laboratory and go to places which resemble Mars on Earth to test future mission equipment under conditions as close to Mars as possible. We also heard about the negative results for the search for life, which have come back from Mars missions since Viking in the seventies but also how these could be explained by the presence of perchlorate, which during heating would burn up organic material before this could have been analyzed. So, there’s still some hope to find relicts of former life on Mars….
The next session was all about space missions and the instruments on spacecrafts which will investigate the behavior of life in space or finding signs of life in solar samples or detecting it in the atmospheres of extraterrestrial planets.
Next up was a session about the ingredients for life, which can be found in meteorites. The main organic molecules everybody is looking for are amino acids, which are an essential building block of life on Earth. But these are by far not the only organic material in meteorites and you will find pretty much every kind of organic molecule you can think of in carbonaceous meteorites which all could have played a role in starting life, which brings us to the next session topic.
“How did life start?” is a question, which is still not answered today although many ideas are discussed. But what seems clear is that is must have been a lot simpler than even the simplest single cells are nowadays. Complex molecules like ADP/ATP, which are essential in the energy transport have not been around and simpler alternatives are discussed as well as places where the right conditions have existed to create the first cells. One of those ideas are thermal vents in the sea, which have a porous structure which would allow to concentrate organic material as well as acting as cell walls allowing the exchange of hydrogen ions without mixing the two different water compositions either side of the wall, which would have stopped any further processing. Later on these inorganic walls must have been replaced by what is now cell membranes but a lot of open questions still need to be solved.
So far these subjects all cover the first question “Where did we come from?” and is tackled from different angles like ‘what organic material was available to start life’ and ‘how can we extrapolate back from current life to this’ but the central point is still not solved.
The second and third of the above questions were subject of the next session, which mainly looked at exoplanets, which could be both, a place to go to as well as a place there extraterrestrial life already exists. Thousands of exoplanets have been discovered by now although many still need confirmation but just the existence of the planet at this point in time is not enough for it to be a habitable as the orbits might well be unstable and lead to destruction of the planets within a very short time before life has a chance to develop if the planet is in a habitable zone in the first place. And not only the orbits of these planets are studied but the next array of spacecraft will also allow us to study their atmospheres and – if the conditions are right – even map the atmosphere although the resolution might be rather low. This should allows us to judge the habitability of exoplanets very well and maybe find signs for extraterrestrial life in the atmosphere depending on its composition.
This brings us to the last session, which was all about SETI and the last of the three questions. SETI is on everybody’s mind ever since the first big citizen science project which used the idle times of home computers to search for signals from extraterrestrial life. The UK community for SETI is rather small but is getting organized to combine forces similar to the efforts already done by the astrobiologists.
Please have a look at the following links for further information about the different organizations involved in this research and the scientists who are trying to solve the questions where do we come from, where do we go and are we alone on this trip:
This list isn’t complete and neither is my narrative but it is what stuck in my head from this conference and I hope you enjoyed the reading and it whetted your appetite for astrobiology. For me it’s time to sign off and catch up on sleep.