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LOS ANGELES – In three years, a new explorer will reach the red planet. The wheels are blowing, the cars are spinning, and the rover will be thrown over the rusty field, looking for rocks to return to Earth – rocks that could once prove life on Mars.
It is for the first time in history that scientists have had a real chance to address one of the most profound questions of humanity: Are we alone?
First, they have to decide where to look.
There are three options: a former source of hot water NASA once visited a dry delta of the river that was introduced into a crater lake and an old mesh network that could have hidden layers of underground water.
Next week, after decades of dreams, years of research, and a three-day debate at a Los Angeles workshop last month, the NASA scientist will choose which space to explore. The site it selects will determine the stage that generations of scientists prove the mysteries of our existence.
The discovery of fossils could illuminate the origins of life on Earth. It could suggest if someone else is there, waiting to be found.
"I want to know," said Matt Golombek, a NASA scientist charged with directing a search for a landing site. – It is not like that? I want to know what's out there. I want to know how big an accident is.
This famine of knowledge is what has attracted hundreds of people to the recent workshop – space explorers and aspiring doctoral students, an 18-year college student and a 80-year-old retired accountant – to assess what the plan was better. For days, they debated, fueled by curiosity and lean coffee, aware that the outcome of their encounter could influence NASA and could change history, aware of what it did not know.
So much about Mars remains a mystery. The very notion of extraterrestrial life is just more than an educated idea stifled by wild hope.
There are hopes.
Why not?
On Earth, microscopic life is inevitable. Biology began here almost four billion years ago when the planet was bombed by the remains of the solar system. Today, small and tenacious microorganisms sneak into the hot springs of Yellowstone National Park, flies in the clouds, freezing in Antarctica, hiding up to a mile and a half below the ground.
If it could happen here, why not?
Mars has been visited by more than two dozen satellites and rovers, which has shown that it is not always the desert world that we see today. The flooded volcanoes and the frozen lava floods show that once the planet had an active interior that led the tectonic activity. Empty canals, rivers and lakes suggest that liquid water has been left to the surface – which could mean a thicker atmosphere to keep the water away from boiling.
Then the disaster struck. Less than a billion years in its history, most experts say the planet's melted core has stopped. This led to the decline of carbon volcanoes and the loss of Mars's magnetic field. Cosmic radiation and energetic particles in the sun have removed the atmosphere of the planet, causing water to evaporate from the surface. Bye, ocean; as long as lakes; farewell from wet soils and volcanic vent holes – all kinds of places that life likes to live.
Mars is seen as a "faulty planet," a frightening version of the alternative reality of the world we live in.
"It is the Earth where the Earth's media disappeared," said Bethany Ehlmann, planetary scientist at Caltech, at the workshop. So the question is: why? And when? "And, most important of all," Life had a chance to go before? "
These questions can only be answered by bringing Mars back to Earth, say most scientists. A man in a cutting-edge lab could analyze the atom of atomic samples, revealing tiny structures that a robot could not see.
Detecting even a few crushed molecules left by a microbe would be historic.
Knowing that biology appeared on two neighboring planets would suggest that life is common throughout the universe. The Martian environment – be it a hot spring, a river delta or an underground refuge – could provide a clue as to where Earth's life came from.
Knowing that a world could keep its life and then fail to point out our unbelievable luck. The conditions for the continual existence of the Earth can not always be so assured.
"We have to take the samples and they have to be the right one," Golombek said.
Behind the ballroom, a researcher turned to the person next to her and grinned: "Are you ready for the showdown?
Silicon structures
The first option for a mission is a Yellowstone thermal springfield explored by Rover Spirit between 2004 and 2010. Here, besides a rocky outing called Home Plate, the defective rover has discovered strange structures similar to the fingers of silica, an associated miner water and life.
The rover was not equipped with tools capable of detecting complex organic compounds, so the mystery of these structures was not solved.
Seven years later, Spirit Operator Steve Ruff received an unlikely epiphany through the volcanology journal: Scientists have discovered a geyser field of the years that contained structures similar to those on Mars. At the site, called El Tatio, micro-organisms that love heat produce silice deposits in filaments, mats, and spirals.
"This is the place most similar to Mars of any set I've ever had," Ruff said.
Reviewing a site could mean that it is less taught, many scientists are worried. What if Ruff is wrong about the silicon structures?
Ruff's answer: "If we are right?"
"If one of the leaders of exploring Mars is to answer this question," Are we alone? "And we find a place to address this question and we turn from it because it is not guaranteed we will find it, I think it's just …" He stopped, looking for a term. "A Conservative," he said "And that's not NASA's characteristic."
Crater of Jezero
If any version of sending a 50 million-mile rover through space can be called "conservative," it could be landing in the Jezero Crater.
It resembles the types of environments in which the ancient fossils on earth were discovered: delta, where sediments accumulate in river basins and are preserved.
"Sedimentary stones tell us the story of what's happening together," said Tim Goudge, a geologist at the University of Texas, Austin. "It is recorded in layers and you can read it as a book."
Lake contains minerals that are associated with life on earth, such as carbonate, as well as soils called smears that are known to "entombe" organic material.
The site is scattered with sand dunes – a potentially fatal danger for a rover.
"I am scaring the beggar from me," said Ray Arvidson, a scientist at Washington University in St. Louis. Louis. In a mission on Mars, there are no reboots.
Diversity of stones
Ehlmann, a scientist at Caltech, spent years looking at the maps of northeastern Syrtis. It is a distinct Martian environment that could be home to a unique Martian life.
"This would be a chance to go there geologist," she said. "I want to look at the cliffs, understand them, discover the story they say."
The site addresses many scientists because of the variety of old rocks they contain.
Residues caused by ancient meteorite effects, called "mega breccias", would be some of the oldest sampled rocks on any planet in the solar system. The cliffs of a billion years younger could reveal how Mars has become the world in which it is.
The area boasts minerals, such as carbonates, which suggest that they once housed an underground aquifer – a potential refuge for organisms seeking protection from the harsh and irregular climate of the planet.
Emily Lakdawalla, a geologist and editor-in-chief of the Planetary Society, posed a question that feared each area under scrutiny.
"And if the evidence does not return?" She said.
Golombek took the microphone. "We decided to base our rules on this conversation," he said. "It all depends on whether you are optimistic or pessimistic, right?"
For now, he urged his colleagues to be optimistic.
Exploring all sites
At the end of the workshop, there was no consensus on the best place to land on the rover. Some scientists have said that their mind has changed with each presentation, their ping-ponging opinions, because they have heard compelling evidence from the supporters of each site. Others have become more rooted in their positions.
And if he should not choose?
The Mission Project Science Team has designed an ambitious, mission-oriented mission centered around a new landing site on the edge of the northeast Syrtis called "Midway," not far from the edge of the Jezero Crater.
It would take hundreds of Martian days – the equivalent of a few years on earth – to make the rover go from one place to another, obtaining the best evidence. Traversa will carry the rover over steep mountain ridges, crowded cliff fields and a dangerous windy field.
"This is an incredibly great exploration," said Ken Williford, deputy scientist of the project.
Even according to Mars' standards, Midway was full of strangers.
Scientists have failed to carry out detailed analyzes of the rocks it contains, and the proposed 15 mile crossing was at the edge of what could be achieved through a wooden rover.
There were many ways in which this could end badly, some worried.
"But," said researcher Ken Farley, "there are several methods of failure."
"Personally," he continued, "I do not want to fail because I was not ambitious enough to make the cache of the scientific sample worthy."
Eventually, the decision will come to Thomas Zurbuchen.
As a NASA associate manager for science, he oversees over 100 missions to understand the solar system and beyond.
"This is the most risky," he said of the $ 2 billion mission. "But suppose everything goes just as we were hoping for. The place of landing on which I am the decision-maker will make history."
Days before being scheduled to receive his final advice on Landing Landing Options, Zurbuchen remained indecisive.
He attended a part of the landing workshop. There were still many things to consider: engineer safety assessments, the potential for future missions, the need to balance astrobiological research with other scientific questions.
Then there was the vision that filled his mind when he closed his eyes to dream – a consideration that was not financial or scientific, but pure hope. A sample carrying Mars samples back to Earth. Scientists recovering cache and get a first look at the pieces of another planet. The laboratory where the rocks will be analyzed, the complex tools that will look for signs of ancient organisms.
A science classroom where his grandchildren sit, read a manual that bears the name of the place he chose – a place where mankind learned for the first time that we were not always alone.
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