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Scientists find evidence of organic molecules on Mars
Updated / Thursday, 7 Jun 2018 19:01
Scientists say they have found definitive evidence of the existence of organic molecules on Mars
By Will Goodbody
Science & Technology Correspondent
Scientists say they have found definitive evidence of the existence of organic molecules on Mars, in a breakthrough that will increase speculation that there was once or is currently life on the red planet.
A separate group of researchers have also conclusively detected methane in the martian atmosphere, the levels of which rise and fall with seasons.
However, in neither case are the teams claiming that their results prove there is or may have been at one time life on Mars.
The discovery of organic molecules was made using the Sample Analysis at Mars (SAM) instrument on NASA's Curiosity rover.
It drilled samples in the Gale Crater area of the planet in a 3.5 billion-year-old formation at Pahrump Hills where it is thought a 100km wide lake once stood.
It then heated the soil to high temperatures, before analysing the gases emitted.
A number of organic based compounds were detected by the instrument.
Before now limited organic compounds had been identified at the Sheepbed mudstone site in the crater.
But these measurements were hampered by the presence of salts which broke down when heated, reacting with the organic molecules during testing.
The discovery does not necessarily mean there is or was once life on Mars. The organic molecules could have been formed by physical processes or may have been transported to Mars by a comet, meteor or asteroid.
However, because the samples were taken from an area where water was once present, scientists think it may point to the one time presence of life.
"We have the ingredients of what we hypothesise to be the formation of life," said Kevin Nolan, lecturer in physics at IT Tallaght.
"Organic material and water with a neutral acidity. So we now know Mars was habitable and we now know all the ingredients for life were there...and this is what we were looking for for a long time," said Mr Nolan.
In a separate paper another team of researchers outline how they definitively detected methane in the martian atmosphere.
Again using SAM, the scientists monitored levels over five years and found not only a stable methane background, but also local seasonal peaks.
The gas, which can be a sign of life, may have been released from a large subsurface reservoir, but neither the source of the methane or what caused its release is understood yet.
Methane can be produced by geology, but sometimes those geological processes can provide a suitable environment for life to emerge.
"If methane was detected there it was generated quite recently," said Mr Nolan.
"The two known processes we know that generate methane are volcanic hydrothermal activity or metabolic activity from life. So either of those scenarios is very good from the prospect again of considering the habitability of Mars."
The discovery is likely to spur on further investigations into the likelihood that organisms once lived or live now on the red planet.
"It basically adds to a picture of a planet that was dynamic and ever changing in its early history in ways similar to Earth and has remained as a dynamic and non-dormant world albeit in a lower level to Earth," said Mr Nolan.
Both papers are published in the latest edition of the journal Science.
https://www.rte.ie/news/world/2018/0607/968981-mars-molecule-discovery/
Updated / Thursday, 7 Jun 2018 19:01
Scientists say they have found definitive evidence of the existence of organic molecules on Mars
By Will Goodbody
Science & Technology Correspondent
Scientists say they have found definitive evidence of the existence of organic molecules on Mars, in a breakthrough that will increase speculation that there was once or is currently life on the red planet.
A separate group of researchers have also conclusively detected methane in the martian atmosphere, the levels of which rise and fall with seasons.
However, in neither case are the teams claiming that their results prove there is or may have been at one time life on Mars.
The discovery of organic molecules was made using the Sample Analysis at Mars (SAM) instrument on NASA's Curiosity rover.
It drilled samples in the Gale Crater area of the planet in a 3.5 billion-year-old formation at Pahrump Hills where it is thought a 100km wide lake once stood.
It then heated the soil to high temperatures, before analysing the gases emitted.
A number of organic based compounds were detected by the instrument.
Before now limited organic compounds had been identified at the Sheepbed mudstone site in the crater.
But these measurements were hampered by the presence of salts which broke down when heated, reacting with the organic molecules during testing.
The discovery does not necessarily mean there is or was once life on Mars. The organic molecules could have been formed by physical processes or may have been transported to Mars by a comet, meteor or asteroid.
However, because the samples were taken from an area where water was once present, scientists think it may point to the one time presence of life.
"We have the ingredients of what we hypothesise to be the formation of life," said Kevin Nolan, lecturer in physics at IT Tallaght.
"Organic material and water with a neutral acidity. So we now know Mars was habitable and we now know all the ingredients for life were there...and this is what we were looking for for a long time," said Mr Nolan.
In a separate paper another team of researchers outline how they definitively detected methane in the martian atmosphere.
Again using SAM, the scientists monitored levels over five years and found not only a stable methane background, but also local seasonal peaks.
The gas, which can be a sign of life, may have been released from a large subsurface reservoir, but neither the source of the methane or what caused its release is understood yet.
Methane can be produced by geology, but sometimes those geological processes can provide a suitable environment for life to emerge.
"If methane was detected there it was generated quite recently," said Mr Nolan.
"The two known processes we know that generate methane are volcanic hydrothermal activity or metabolic activity from life. So either of those scenarios is very good from the prospect again of considering the habitability of Mars."
The discovery is likely to spur on further investigations into the likelihood that organisms once lived or live now on the red planet.
"It basically adds to a picture of a planet that was dynamic and ever changing in its early history in ways similar to Earth and has remained as a dynamic and non-dormant world albeit in a lower level to Earth," said Mr Nolan.
Both papers are published in the latest edition of the journal Science.
https://www.rte.ie/news/world/2018/0607/968981-mars-molecule-discovery/
