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Competition: Win a piece of Mars
competition
Meteorite fragments from the Red Planet can hold traces of Martian life, says planetary scientist Colin Pillinger – and you can win one in our exclusive competition
Your own piece of Mars 38 | NewScientist | 21 May 2011
corbis /Open University
A prize that is out of this world New Scientist is offering you the opportunity to win your very own piece of Mars. Just tell us in no more than 140 characters what you think the first person to set foot on Mars should say. The winner will receive a 1.76-gram piece of the Mars meteorite NWA 2975 that landed in north-west Africa. The rock, pictured above, has been authenticated by the Open University, UK. So can you better the phrase Neil Armstrong used when he stepped onto the moon: “One small step for man, one giant leap for mankind”? For details of how to enter go to newscientist.com/marsrock
the existence of water on Mars. That’s because they contain minerals such as carbonates, which are likely to have been precipitated from water. Orbiting spacecraft have never managed to locate these minerals in copious quantities, though NASA’s Polar Lander did find various salts that might have originated in a similar way. There is plenty of other evidence that water, the key ingredient needed by life, has been present on Mars for a long time. NASA’s orbiters and ESA’s Mars Express have found surface features that can only have been made by large quantities of water perhaps 3 billion years ago. This is consistent with the age of the carbonate deposits in Mars meteorites, which have been dated using radioisotopes to originating as early as 3.9 billion years ago.
Vital signs Studies of Martian meteorites have outpaced the findings made by NASA’s rovers, too. In 1978, Robert Hutchison at the Natural History Museum in London found evidence in a Martian meteorite of minerals deposited by water – more than 25 years before similar evidence was uncovered by Steve Squyres and his team at NASA, thanks to the Spirit and Opportunity rovers. Meteorites have, of course, given rise to the most widely publicised suggestion that life may once have thrived on the Red Planet. The rock, known as ALH 84001, came down in Allan Hills, Antarctica, around 13,000 years ago. In August 1996, US president Bill Clinton announced what he called “stupendous” news: Everett Gibson and his colleagues at NASA had discovered what appeared to be a nanometre-sized fossil within ALH 84001. But this was not the first time a Martian meteorite had yielded evidence of life. In 1989, at the Open University, we made a remarkable discovery in another meteorite also from Antarctica, called EETA 79001. Within the carbonate present in the meteorite,
we found a measurable proportion of organic material, typical of that left by the remains of living things on Earth. We stopped short of saying we had discovered life on Mars, preferring, like good scientists, to remain sceptical. In our paper, we merely said that if we are correct “the implications are obvious” (Nature, vol 340, p 220). Later, in the furore surrounding ALH 84001, I found myself being described in the press as “the man who missed life on Mars”. After the fuss had died down, geologists and biologists began to question the validity of ALH 84001’s supposed fossil and the organic material we had reported. Some preferred to believe that the fossil was an artefact and that the organic material was contamination picked up after the meteorite landed in Antarctica. Nevertheless I was convinced our findings were real. It was this that provided the impetus for the Beagle 2 mission. Since 1996 we have analysed several more carbonate deposits in EETA 79001. The organic materials are confined to one part of the rock, which would seem to exclude the possibility of contamination because there is no obvious way extraneous carbon could find its way into just one bit of the rock and not others. In any case, Antarctic melt water contains such small amounts of carbon that vast amounts of water would need to have percolated though the meteorite to accumulate the organics we found. It is eight years since Beagle 2 didn’t call home and it looks like being at least that long until another lander sends back any information about life on Mars. So we will just have to wait – unless, of course, some hitherto undiscovered secret is found hiding in another meteorite. Maybe there is one lurking in the piece of Mars that you could win. n Colin Pillinger is a professor of planetary science at the Open University, Milton Keynes, UK. His autobiography, My life on Mars (the Beagle 2 diaries) is published by the British Interplanetary Society 21 May 2011 | NewScientist | 39
not actual size
W
HEN is there going to be another mission to look for life on Mars? It is a question I have been asked time and again since Christmas Day 2003, when my team lost contact with our Beagle 2 lander. It was due to call home at 0528 GMT that morning, after landing on the surface of Mars, but there was only silence. Beagle 2 was carrying an instrument that I believe could have detected traces of living things on the Red Planet. None of the three landers that NASA has since successfully sent to Mars has had the ability to do anything similar. NASA initially agreed to work with the European Space Agency (ESA) on a mission to send two rovers to search for life, planned for 2018. But it announced this year that budget constraints would require a rethink that could mean major reductions in these vehicles’ payload and capabilities. ESA itself initially promised there would be a follow-up mission to search for life as soon as 2007, but that date has slipped many times. Fortunately, none of this means we have to give up on looking for evidence of life on Mars. We have a remarkable resource in the form of fragments of Martian rock blasted from the planet’s surface by an asteroid impact, which have ended up landing on Earth many thousands of years later. We know of more than 90 examples of such Martian meteorites, although some come from the same object that disintegrated in the atmosphere. Many of them have been recovered from the deserts of north Africa, including one called NWA 2975 – a piece of which New Scientist is offering as a prize (see “A prize that is out of this world”). We know these fragments come from Mars because all meteorites contain clues about their origins. Buried inside some are small pockets of glass formed during the asteroid impact, which can contain traces of gas. Measurements of the composition of this gas match the analysis of the Martian atmosphere by NASA’s Viking landers in the 1970s – a discovery that provided the first confirmation that some meteorites found on Earth really do come from Mars. Another indicator of a meteorite’s origin is the relative abundance of three isotopes of oxygen – oxygen-16, oxygen-17 and oxygen-18 – in the molecules of silicate they contain. Because the relative abundance of these isotopes varies throughout the solar system, it is possible to establish whether a meteorite comes from the moon, the asteroid belt or Mars. At the Open University, we pioneered a method in which we use a laser to melt the silicate minerals in the presence of chemicals that liberate oxygen, and then make very precise isotope measurements. Meteorites from Mars have a slight excess in the abundance of oxygen-17. This is how we authenticated the prize meteorite. Martian meteorites can also tell us about
Meteorite fragments from the Red Planet can hold traces of Martian life, says planetary scientist Colin Pillinger – and you can win one in our exclusive competition
Your own piece of Mars 38 | NewScientist | 21 May 2011
corbis /Open University
A prize that is out of this world New Scientist is offering you the opportunity to win your very own piece of Mars. Just tell us in no more than 140 characters what you think the first person to set foot on Mars should say. The winner will receive a 1.76-gram piece of the Mars meteorite NWA 2975 that landed in north-west Africa. The rock, pictured above, has been authenticated by the Open University, UK. So can you better the phrase Neil Armstrong used when he stepped onto the moon: “One small step for man, one giant leap for mankind”? For details of how to enter go to newscientist.com/marsrock
the existence of water on Mars. That’s because they contain minerals such as carbonates, which are likely to have been precipitated from water. Orbiting spacecraft have never managed to locate these minerals in copious quantities, though NASA’s Polar Lander did find various salts that might have originated in a similar way. There is plenty of other evidence that water, the key ingredient needed by life, has been present on Mars for a long time. NASA’s orbiters and ESA’s Mars Express have found surface features that can only have been made by large quantities of water perhaps 3 billion years ago. This is consistent with the age of the carbonate deposits in Mars meteorites, which have been dated using radioisotopes to originating as early as 3.9 billion years ago.
Vital signs Studies of Martian meteorites have outpaced the findings made by NASA’s rovers, too. In 1978, Robert Hutchison at the Natural History Museum in London found evidence in a Martian meteorite of minerals deposited by water – more than 25 years before similar evidence was uncovered by Steve Squyres and his team at NASA, thanks to the Spirit and Opportunity rovers. Meteorites have, of course, given rise to the most widely publicised suggestion that life may once have thrived on the Red Planet. The rock, known as ALH 84001, came down in Allan Hills, Antarctica, around 13,000 years ago. In August 1996, US president Bill Clinton announced what he called “stupendous” news: Everett Gibson and his colleagues at NASA had discovered what appeared to be a nanometre-sized fossil within ALH 84001. But this was not the first time a Martian meteorite had yielded evidence of life. In 1989, at the Open University, we made a remarkable discovery in another meteorite also from Antarctica, called EETA 79001. Within the carbonate present in the meteorite,
we found a measurable proportion of organic material, typical of that left by the remains of living things on Earth. We stopped short of saying we had discovered life on Mars, preferring, like good scientists, to remain sceptical. In our paper, we merely said that if we are correct “the implications are obvious” (Nature, vol 340, p 220). Later, in the furore surrounding ALH 84001, I found myself being described in the press as “the man who missed life on Mars”. After the fuss had died down, geologists and biologists began to question the validity of ALH 84001’s supposed fossil and the organic material we had reported. Some preferred to believe that the fossil was an artefact and that the organic material was contamination picked up after the meteorite landed in Antarctica. Nevertheless I was convinced our findings were real. It was this that provided the impetus for the Beagle 2 mission. Since 1996 we have analysed several more carbonate deposits in EETA 79001. The organic materials are confined to one part of the rock, which would seem to exclude the possibility of contamination because there is no obvious way extraneous carbon could find its way into just one bit of the rock and not others. In any case, Antarctic melt water contains such small amounts of carbon that vast amounts of water would need to have percolated though the meteorite to accumulate the organics we found. It is eight years since Beagle 2 didn’t call home and it looks like being at least that long until another lander sends back any information about life on Mars. So we will just have to wait – unless, of course, some hitherto undiscovered secret is found hiding in another meteorite. Maybe there is one lurking in the piece of Mars that you could win. n Colin Pillinger is a professor of planetary science at the Open University, Milton Keynes, UK. His autobiography, My life on Mars (the Beagle 2 diaries) is published by the British Interplanetary Society 21 May 2011 | NewScientist | 39
not actual size
W
HEN is there going to be another mission to look for life on Mars? It is a question I have been asked time and again since Christmas Day 2003, when my team lost contact with our Beagle 2 lander. It was due to call home at 0528 GMT that morning, after landing on the surface of Mars, but there was only silence. Beagle 2 was carrying an instrument that I believe could have detected traces of living things on the Red Planet. None of the three landers that NASA has since successfully sent to Mars has had the ability to do anything similar. NASA initially agreed to work with the European Space Agency (ESA) on a mission to send two rovers to search for life, planned for 2018. But it announced this year that budget constraints would require a rethink that could mean major reductions in these vehicles’ payload and capabilities. ESA itself initially promised there would be a follow-up mission to search for life as soon as 2007, but that date has slipped many times. Fortunately, none of this means we have to give up on looking for evidence of life on Mars. We have a remarkable resource in the form of fragments of Martian rock blasted from the planet’s surface by an asteroid impact, which have ended up landing on Earth many thousands of years later. We know of more than 90 examples of such Martian meteorites, although some come from the same object that disintegrated in the atmosphere. Many of them have been recovered from the deserts of north Africa, including one called NWA 2975 – a piece of which New Scientist is offering as a prize (see “A prize that is out of this world”). We know these fragments come from Mars because all meteorites contain clues about their origins. Buried inside some are small pockets of glass formed during the asteroid impact, which can contain traces of gas. Measurements of the composition of this gas match the analysis of the Martian atmosphere by NASA’s Viking landers in the 1970s – a discovery that provided the first confirmation that some meteorites found on Earth really do come from Mars. Another indicator of a meteorite’s origin is the relative abundance of three isotopes of oxygen – oxygen-16, oxygen-17 and oxygen-18 – in the molecules of silicate they contain. Because the relative abundance of these isotopes varies throughout the solar system, it is possible to establish whether a meteorite comes from the moon, the asteroid belt or Mars. At the Open University, we pioneered a method in which we use a laser to melt the silicate minerals in the presence of chemicals that liberate oxygen, and then make very precise isotope measurements. Meteorites from Mars have a slight excess in the abundance of oxygen-17. This is how we authenticated the prize meteorite. Martian meteorites can also tell us about