Image credit: Beagle 2
Colin Pillinger is married and has two children. He lives on a small farm in Cambridgeshire, where his livestock keep him busy out of working hours. He first became interested in ‘space science’ by reading Dan Dare comics and listening to ‘Journey Into Space’ on the radio.
“The loss of Beagle-2 I would say was very frustrating to everyone who worked on the project including myself, because the craft carried the first instruments down onto the Martian surface that would actually look for Carbon based organisms, as apposed to carrying out a chemical analysis of the Martian soil by adding liquid nutrients, which is what the Label Release Experiment did on the Vikings landers back in 1976,” explained Professor Pillinger.
2004 has truly been ‘The year of Mars’ with the European Space Agency’s Mars Express doing remarkable science in Martian orbit, while sending back highly detailed images of the planet, and with the successful landing of the two NASA/JPL rovers Spirit and Opportunity in January which have done good geological science leading to the discovery that a huge quantity of water once flowed on the red planet.
“Finding out that a large amount of water existed on Mars in the past was good news because it brings the possibility of some form of life on the planet that bit closer,” explained Colin. “Meteorites from Mars that have landed on Earth show clear evidence that conditions appropriate to life did exist on the red planet, including in the recent past.
“However, features in the meteorites which have been described as nanofossils are highly controversial. Unfortunately, we cannot be sure that organic matter found in the meteorites is the remnant of organisms that lived on Mars and not due to contamination on Earth. We need to repeat the experiments on rocks that never left Mars,” he continued.
A short time ago I talked to Sir Patrick Moore about the best chance of finding life in the solar system, and I posed this question to Professor Pillinger as well. In our interview, Sir Patrick had said, “I believe our best chance of finding life is on the planet Mars. We now know that a lot of water once existed on this planet sometime in the past, and the latest surface rovers (Spirit and Opportunity), along side orbiting space probes like Mars Express, have shown that the Martian conditions are more favorable for life to evolve their today than at any time in the past. If the conditions are right, life will always find a way to exist.”
Prof. Pillinger replied “The fact that Mars Express has also confirmed the existence of methane in the thin Martian atmosphere, is interesting too.
“There have been two independent astronomical observations that first detected the presence of methane while Mars Express just confirmed it, and we now know that the amount of this gas is more than can be accounted for by volcanic activity.”
On Earth, there are many creatures, large and small, that produce methane. The simplest biological sources, including peat bogs, rice fields and ruminant animals (cows, sheep, etc.), continuously supply fresh gas to replace that destroyed by oxidation.
Methane also has a very short lifetime on Mars because of the oxidizing nature of the atmosphere, so its presence would indicate a replenishing source, which may be life, even if it is buried beneath the surface. If this methane exists, the Mars Express Orbiter has an instrument which should be able to detect it in the atmosphere.
“The Beagle-2 lander would have looked for signatures of life on Mars, whether long-dead or still-living, by measuring the ratio of two different types of carbon in the rock,” explained Prof. Pillinger. “Biological processes on Earth favor the lighter isotope of carbon, carbon-12, over the heavier carbon-13. Hence, a high carbon-12 to carbon-13 ratio is taken as evidence of life and has been found in rocks up to 4000 million years old, even where geological processing has occurred.”
Dr. Gilbert V. Levin, an experimenter with the original 1976 Viking Mission to Mars has been following this methane discovery with great interest. He has been advocating for years that Viking did find evidence of life on Mars with the Labeled Release life detection experiment, but other scientists are still skeptical.
I asked Colin if the discoveries by Spirit and Opportunity in 2004, or the recent discovery of methane supported Dr. Levin’s findings.
“I have heard of Dr. Levin. I think it is a firm understanding among planetary scientists that the Viking life investigation experiment only detected a chemical reaction rather than finding life on Mars itself. There is no point in harking on about the past, it’s time to move on and look for the real evidence of the carbon-based organisms that may exist on Mars today. That is where the Beagle 2 experiment differed from that of the Viking landers.”
Is there any other evidence that life may exist on the red planet, I asked? “Yes, meteorites from Mars that have landed on Earth show clear evidence that conditions appropriate to life did exist on the planet, including in the recent past, unfortunately, we cannot be sure that organic matter found in the meteorites is the remnant of organisms that lived on Mars and not due to contamination on Earth. We need to repeat the experiments on rocks that never left the Red Planet.
“At the moment there is no new Beagle Mars Lander project; however, I think this is an exciting time to look for life on Mars, and Beagle was well equipped to try and find it, which is why it has been very frustrating for my team and myself. I think that a new British Beagle lander should be built at this time to go to Mars and look for signs of life on the planet’s surface.”
By Science Correspondent Richard Pearson