LOS ANGELES – In three years, the new researcher will touch the Red Planet. Wheels tamped, rotating machines, a rover runs on rusty terrain, looking for rocks that can be sent back to Earth – rocks that could prove that life was once on Mars.
For the first time in history, scientists have tried to answer one of humanity's deepest questions: Are we alone?
First of all, they have to decide where to look.
There are three options: the former hot spring NASA visited once, the dried out delta of the river that feeds the crater lake, and a network of ancient meshes that can have hidden layers of underground water.
In the coming week, after years of dreams, years of research and a three-day debate at a workshop in Los Angeles last month, NASA's chief scientific officer will choose this place to explore. The website he chooses will be the stage at which generations of scientists will investigate the mysteries of our existence.
The discovery of fossils can illuminate the sources of life on Earth. This may indicate whether someone is there, waiting to be found.
"I want to know," said Matt Golombek, a NASA scientist who was entrusted with searching for the landing site. "Do not you? I want to know what's up there. I want to know how big the accident is.
This hunger for knowledge has attracted hundreds of people to recent workshops – space explorers and aspiring doctoral students, an 18-year college first-year student and an 80-year-old retired accountant – to assess which plan is the best. They spent many days debating, fueled by curiosity and weak coffee, aware that the outcome of their meeting could affect NASA and shape history, perfectly aware of what they do not know.
So much about Mars remains a mystery. The very concept of a foreign life is only an educated guess supported by wild hope.
They are full of hope.
On Earth, microscopic life is inevitable. Biology began here almost 4 billion years ago, when the planet was bombarded by debris remaining after the formation of the Solar System. Today, small, stubborn organisms spatter in the hot springs of Yellowstone National Park, flying in the clouds, freezing in Antarctica, lurking at a depth of one and a half kilometers underground.
If it could happen here, why not?
Mars has visited over two dozen satellites and rovers, which have shown that this is not always the empty world we see today. Dormant volcanoes and frozen floods of lava show that once the planet had an active interior that fueled tectonic activity. Empty canals, ravines and lakes suggest that the liquid water once hit the surface – which can mean a denser atmosphere, so that the water does not boil.
Then the catastrophe struck. Less than a billion years ago, most experts say the liquid core of the planet has stopped spinning. This led to the fall of carbon volcanoes and the loss of the protective magnetic field of Mars. The cosmic and energetic rays of the solar particles have denied the atmosphere of the planet, causing evaporation of all water on the surface. Goodbye, ocean; for so long, lakes; Saying goodbye to moist soils and bubbles of volcanic holes – all kinds of places that he likes to live.
Mars is perceived as a "failed planet", a terrifying alternative reality of the world in which we live.
"This is Earth, where Earth's environment has gone," Bethany Ehlmann, a planetary scientist from Caltech, said during the workshop. "So the question is, why? And when?" And, most importantly, "Did life have a chance to get through earlier?"
These questions can only be answered by restoring Mars rocks to Earth, as most scientists say. A man in a top-level laboratory would be able to analyze atom-by-atom samples, revealing tiny structures that the robot could not see.
Detecting even a few tattered particles left by microbes would be historic.
The knowledge that biology was created on two neighboring planets would suggest that life is common throughout the universe. The environment in which the Martians are located – be it a hot spring, a delta river or an underground shelter – can be a hint where life on Earth comes from.
Awareness that the world can survive life and then fail will emphasize our incredible prosperity. Conditions for the continued existence of Earthlings can not always be guaranteed.
"We must get these samples and they must be appropriate," said Golombek.
In the back of the ballroom, one researcher turned to the person next to her and smiled: "Are you ready for the final game?"
The first option for the mission is a field of hot sources similar to Yellowstone discovered by the Spirit's rover in 2004-2010. Here, next to the rocky discoverer called Home Plate, the inactive tramp discovered a strange, finger-like structure of silica, a mineral associated with water and life.
The rover was not equipped with instruments capable of detecting complex organic compounds, so the puzzle of these structures has not been solved.
Seven years later, the operator of Spirit instruments, Steve Ruff, received an unbelievable revelation thanks to a volcanic magazine: Scientists have discovered an unearthly field of geysers in the Andes that contained structures similar to those on Mars. In the place called El Tatio, heat-loving microorganisms produce silica deposits in fibers, mats and spiers.
"This is the place that most resembles Mars in any setting I've ever been in," said Ruff.
Re-visiting the site may mean that there is less learning, many scientists are worried. What if Ruff is wrong about silica structures?
Ruff's answer: "What if we are right?"
"If one of the factors exploring Mars is to answer this question:" Are we alone? "And we find a place that can answer that question and we turn away from it because there is no guarantee that we will find it, I think it's just …" He paused, looking for a date. "Conservatism," he finally said. "And it just is not characteristic of NASA."
If any version of the 50 million rover sending through the cosmos can be called "conservative", landing in the Jezero Crater can be it.
It is most reminiscent of the environments in which ancient fossils on the Earth have been discovered: the delta, where sediments from extensive water bodies gather and preserve.
"The sedimentary rocks tell us about the history of what was happening in the place," said Tim Goudge, a geologist at the University of Texas at Austin. "It's recorded on layers and can be read like a book."
Jezero contains minerals associated with life on Earth, such as carbonate, as well as clays called smectites, which are known to "absorb" organic material.
The site is dotted with dunes – a potentially fatal jeopardy.
"They scared me about it," said Ray Arvidson, a scientist at Washington University in St. Louis. There are no reboots in the mission to Mars.
Variety of rocks
Ehlmann, a scientist from Caltech, spent years on mes maps in north-east Syrtis. This is clearly a Martian environment that can be the home of an extremely Martian life.
"It would be a chance to become a geologist there," she said. "I want to look at the rocks, understand them, unravel the story they tell."
This place appeals to many scientists because of the variety of ancient rocks that it contains.
Shards from ancient meteorite impacts, called "mega breccia", were one of the oldest rocks taken from every planet in the Solar System. Rocks a billion years younger can reveal how Mars has become this world.
In the area there are minerals, such as carbonates, which suggest that once was an underground aquifer – a potential refuge for organisms seeking protection from the harsh and changing climate of the planet.
Emily Lakdawalla, a geologist and senior editor of the Planetary Society, asked a question that emerges from every contemplated place.
"What if the samples will not be returned?" – she said.
Golombek took the microphone. "We decided to justify this conversation," he said. "It all depends on whether you are an optimist or a pessimist, right?"
For now, he encouraged his colleagues, he was an optimist.
Discovering all pages
The last morning of the workshop there was no agreement as to the best place to unload the rover. Some scientists say their minds changed with each presentation, and their opinions were pinged when they heard convincing evidence from the followers of every site. Others have become more established in their positions.
What if they did not have to choose?
The mission team's scientific team has developed an ambitious, expanded mission centered around a new landing site on the north-east Syrtis, called "Midway," near the edge of the Jezero Crater.
It takes hundreds of Martian days – the equivalent of several years on Earth – that the rover can hit from one side to the other, obtaining the best samples. Traverse will drive the rover through steep mountain ridges, crowded rocks and dangerous wind.
"It's an amazingly big discovery," said Ken Williford, deputy mission scientist.
Even according to Mars' standards, Midway was full of unknowns.
Scientists have been unable to carry out a detailed analysis of the rocks it contains, and the proposed 15-mile traverse was on the brink of what can be achieved with a rickety rover.
There were many ways that could end badly, others are worried.
"But" – project scientist Ken Farley objected – "there is more than one way to fall."
"Personally," he continued, "I do not want to fail because we were not ambitious enough to make the sample cache valuable scientifically."
Ultimately, the decision boils down to Thomas Zurbuchen.
As an administrative partner in science, NASA oversees over 100 missions to understand the Solar System and beyond.
"It is the most risky" – he said about a mission worth $ 2 billion. "But let's assume everything goes exactly the way we expected it. The landing site I'm officially official will create a story.
A few days before the planned arrival of the final information on the landing options, Zurbuchen remained undecided.
He participated in part of the landing workshop. There was still so much to consider: an assessment of the safety of engineers, the potential for further missions, the need to balance astrobiological research with other scientific questions.
Then there was a vision that filled his mind when he closed his eyes to dream – a consideration that was neither financial nor scientific but pure hope. A probe that transports Mars samples to Earth. Researchers taking cache memory and first glance at fragments of another planet. A laboratory in which rocks will be analyzed, complex instruments that will look for traces of ancient organisms.
In the scientific class in which his future grandchildren are sitting, reading a textbook that bears the name of the place he chose – the place where humanity learned, for the first time we were not always alone.