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life on Mars
Scientists have concluded that is 99% certain there is life on Mars after a mathematical analysis of the Red Planet soil samples taken by Viking 1 probe on July 1976.
Viking 1 did find evidence of extraterrestrial microbes in soil samples from the Red Planet.
Mathematical analysis of the samples concluded that salts in the soil on Mars “threw off” initial estimates – and that the soil samples show strong evidence of microbial life.
The new analysis looked for “complexity” in the samples – an indication of life. To the surprise of the scientists, they found it.
“This suggests a robust biological response,” say the researchers, from the University of Siena and California’s Keck Institute.
“These analyses support the interpretation that the Viking LR experiment did detect extant microbial life on Mars.”
Viking 1 probe did find evidence of extraterrestrial microbes in soil samples from Mars
The reassessment was prompted by the discovery of “perchlorates” in the soil at the landing site of another Mars lander, Phoenix, in 2008.
The presence of the chemicals in Viking’s samples had led scientists to conclude the samples were contaminated.
The scientists behind the experiment remain divided over how conclusive the evidence for life on Mars is.
Christopher McKay of NASA’s Ames Research Centre said in an interview with Discovery News: “Finding organics is not evidence of life or evidence of past life. It’s just evidence for organics.”
“The ultimate proof is to take a video of a Martian bacteria. They should send a microscope — watch the bacteria move,” said Josheph Miller of USC’s Keck School of Medicine.
“On the basis of what we’ve done so far, I’d say I’m 99 percent sure there’s life there.”
Future Mars missions may be able to settle the question.
One forthcoming unmanned mission is the new Mars Science Laboratory rover, called Curiosity, scheduled for launch in November.
The $2.5 billion nuclear-powered machine will land on Mars’ surface with a suite of 10 science instruments to try to determine if conditions are favorable for life.
Another key Mars mission is scheduled for 2016. Called the ExoMars Trace Gas Orbiter, it will carry five science instruments and will study gases in Mars’ atmosphere, including methane, for evidence of biological or geological activity.
“The instruments on that atmospheric mission have a factor of 100 to 1,000 increase in sensitivity over what is currently available from Mars orbiters or from ground observations,” said Mark Allen, Ph.D., who is the U.S. project scientist for the 2016 Mars mission.
Scientists from Oregon State University have collected microbes from an icy “lava tube” in mountains in Oregon – similarly hostile to the Red Planet’s surface – and found common microbes thriving.
The research team said that the microbes “lived” on iron from a mineral found in rocks – a mineral, olivine, also found in volcanic rocks on Mars, and could survive low oxygen conditions and the total absence of organic food.
“This microbe is from one of the most common families of bacteria found on Earth,” said Amy Smith, a doctoral student at Oregon State University and one of the authors of the study.
“You can find its cousins in caves, on your skin, at the bottom of the ocean and just about anywhere. What is different, in this case, is its unique qualities that allow it to grow in Mars-like conditions.”
Oregon State University research team said that the microbes “lived” on iron from a mineral found in rocks - a mineral, olivine, also found in volcanic rocks on Mars, and could survive low oxygen conditions and the total absence of organic food
The Oregon State University scientists proved that microbes have adapted to deal with their harsh living conditions.
In a normal, room-temperature settings, with normal oxygen levels, the bacteria eat organic materials such as sugar.
But the researchers removed the food, turned down the temperature to near-freezing and lowered the oxygen, they turned to the food they survive on in the lava tubes – olivine, a common mineral found in volcanic rocks on Earth and on Mars – as its energy source.
Martin Fisk, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences and an author on the study said:
“This reaction – where microbes <<feed>> on a common mineral from volcanic rocks – just hasn’t been documented before.”
In volcanic rocks directly exposed to air and at warmer temperatures, the oxygen in the atmosphere oxidizes the iron before the microbes can use it.
But in the lava tube, where the bacteria are covered in ice and thus sheltered from the atmosphere, they out-compete the oxygen for the iron.
The microbes were collected from a lava tube near Newberry Crater in Oregon’s Cascades Mountains, at an elevation of about 5,000 feet. They were within the ice on rocks some 100 feet inside the lava tube, in a low-oxygen, near-freezing environment.
Scientists, including Prof. Martin Fisk, have said that the subsurface of Mars could have similar conditions and harbor bacteria.
In fact, Prof. Martin Fisk has examined a meteorite originating from Mars that contained tracks – which could indicate consumption by microbes – though no living material was discovered.
Similar tracks were found on the rocks from the Newberry Crater lava tube, he said.
“Conditions in the lava tube are not as harsh as on Mars,” Prof. Martin Fisk said.
“On Mars, temperatures rarely get to the freezing point, oxygen levels are lower and at the surface, liquid water is not present. But water is hypothesized to be present in the warmer subsurface of Mars. Although this study does not exactly duplicate what you would find on Mars, it does show that bacteria can live in similar conditions.
“We know from direct examination, as well as satellite imagery, that olivine is in Martian rocks.
“And now we know that olivine can sustain microbial life.”
Australian scientists, who have made an overall study of temperature and pressure conditions of Mars, say that a greater percentage of the Red Planet is habitable than Earth.
Scientists from the Australian National University say that 3% of Mars could sustain life, while just one per cent of Earth’s volume contains life – from the core to upper atmosphere.
However, the researchers say that most Earth-like organisms would need to retreat underground to survive on Mars.
Astrobiologist Charley Lineweaver told AFP: “What we tried to do, simply, was take almost all of the information we could and put it together and say <<is the big picture consistent with there being life on Mars?>>” And the simple answer is yes… There are large regions of Mars that are compatible with terrestrial life.”
Life could exist on Mars, scientists say, largely because there is a huge amount of water there in the form of ice, found at the polar regions.
But the pressure on the planet is so low that water would vaporize on the surface.
Below ground, however, there is sufficient pressure for water to be kept in a liquid state, which would enable microbes to thrive.
And while the surface temperature is not ideal for life, being an extremely chilly -65C, below ground it would be much warmer thanks to heat from the planet’s core.
Charley Lineweaver added that his study, which analyzed decades of data, was “the best estimate yet published of how habitable Mars is to terrestrial microbes”.
His findings were published today in Astrobiology.
Australian scientists, who have made an overall study of temperature and pressure conditions of Mars, say that a greater percentage of the Red Planet is habitable than Earth
Scientists will learn a great deal more about Mars’s ability to sustain life when the rover Curiosity lands on the surface next August.
NASA’s earlier Viking rovers concluded 35 years ago that there was no sign of life, but scientists hope Curiosity’s more sophisticated equipment will reveal more.
It will be “the largest and most complex piece of equipment ever placed on the surface of another planet”, said Doug McCuistion, director of NASA’s Mars exploration programme.
Curiosity rover is expected to land on Mars on August 5, 2012, after travelling nearly 354 million miles from our planet.
One of the chief tasks of the $2.5billion mission will be to discover the source of the methane gas scientists have detected in the Martian air.
It will also fire a laser beam with the energy of a million lightbulbs at the surface of the red planet to see whether or not it could have supported life.
The international team of space explorers that launched the Mars Science Laboratory is relying on the instrument to look for biological signs on the distant world.
The ChemCam will fire a powerful laser pulse, vaporising some Mars dust and examining the spectrum of light shining through it.
The robust system is one of 10 instruments mounted on the mission’s rover vehicle.
When ChemCam fires its extremely powerful laser pulse, it will vaporize an area the size of a pinhead.
The system’s telescope will peer at the flash of glowing plasma created by the vaporized material and record the colours of light contained within it.
These spectral colours will then be interpreted by a spectrometer, enabling scientists to determine the elemental composition of the vaporized material.
