Mars 2020 will hunt for 'microfossils', signs of ancient alien life
The Jerezo crater — where Mars 2020 is set to land — could be a good place to find signs of past life on Mars.
- The Jerezo crater is likely home to hydrated silica, a material which on Earth is especially good at preserving signs of life.
- Mars 2020 is set to land on the planet crater in February 2021. NASA's Curiosity rover is currently the only rover operating on Mars.
- The discovery of past life on Mars would be revolutionary, at least in science and philosophy.
The Mars 2020 rover is set to search for signs of past alien life when it lands on the red planet in 2021.
NASA hopes to land the rover on Mars' Jerezo crater, a site which — according to recent observations from the Mars Reconnaissance Orbiter — is likely home to hydrated silica, a mineral known to preserve signs of life on Earth. A paper recently published in the journal Geophysical Research Letters describes how this material might contain biosignatures left behind by tiny alien lifeforms billions of years ago. In short, it's a fossil hunt — a microfossil hunt, more precisely.
"The oldest evidence — definitive evidence — of microfossils that we have on Earth are usually found in silica," Jesse Tarnas, a planetary scientist at Brown University and one of the authors of the paper, told Astronomy.
Today, Mars is essentially a vast desert with a thin atmosphere that — according to almost all scientists — cannot support life. But it's possible that the red planet supported life a few billion years ago, during the Noachian period. There's evidence, for example, suggesting that rivers raged on Mars within the past billion years (liquid water is believed to be necessary for all lifeforms).
Some of these rivers used to flow through the part of Mars that is now Jerezo crater, and they carved a delta into the planet's surface. It's here that Mars 2020 might find hydrated silica, a crystalline material that might have formed in the delta, or elsewhere on the planet (volcanoes, for example), from which it was carried to the delta by rivers.
Mars 2020 will be able to analyze any hydrated silica it finds. But to confirm the existence of biosignatures within that material, the rover will need to take samples to be brought back to Earth so scientists can analyze them in the lab. However, it's possible that some rocks on Mars contain fossils large enough for the rover to photograph.
In addition to searching for microfossils, Mars 2020 will help scientists learn more about the planet's surface and future landing sites, and it will also bring samples of spacesuits to the planet so scientists can study how the materials degrade when subjected to the Martian environment.
What would the discovery of life on Mars mean?
Finding signs of life on Mars would finally settle the longstanding question: Is Earth the only planet capable of supporting life? If Mars 2020 does find biosignatures on Earth's neighbor, it would suggest that life almost surely exists throughout the universe. The discovery would be revolutionary, at least in science and philosophy.
"I think such a discovery would be momentous, more momentous than the Copernican Revolution, but philosophically very similar," David Weintraub, a professor of astronomy at Vanderbilt University, told Gizmodo. "Pre-Copernicus, most thinkers — whether for religious or philosophical or metaphysical reasons — accepted that Earth was the center of the universe and thus that we were likely the center of creation and of God's attention... Copernicus de-centered humanity. The discovery of life beyond the Earth will, similarly, decenter humanity. Life on Earth would no longer be unique. Honestly, I can't think of a more momentous discovery."
Yet, the discovery of life on Mars probably wouldn't change day-to-day life much, or send our belief systems and social institutions into chaos. After all, the world has already been through a test run of the "alien life" announcement: In 1996 researchers from NASA's Johnson Space Center published claims suggesting that a Martian meteorite called Allan Hills 84001 contained microfossils. Skeptics later noted that these supposed biosignatures likely came from inorganic processes. But throughout that process, the public's reaction seemed to be slightly-more-than-normal interest in the news story.
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The idea of 'absolute time' is an illusion. Physics and subjective experience reveal why.
- Since Einstein posited his theory of general relativity, we've understood that gravity has the power to warp space and time.
- This "time dilation" effect occurs even at small levels.
- Outside of physics, we experience distortions in how we perceive time — sometimes to a startling extent.
Physics without time<p>In his book "The Order of Time," Italian theoretical physicist Carlo Rovelli suggests that our perception of time — our sense that time is forever flowing forward — could be a highly subjective projection. After all, when you look at reality on the smallest scale (using equations of quantum gravity, at least), time vanishes.</p><p style="margin-left: 20px;">"If I observe the microscopic state of things," writes Rovelli, "then the difference between past and future vanishes … in the elementary grammar of things, there is no distinction between 'cause' and 'effect.'"</p><p>So, why do we perceive time as flowing <em>forward</em>? Rovelli notes that, although time disappears on extremely small scales, we still obviously perceive events occur sequentially in reality. In other words, we observe entropy: Order changing into disorder; an egg cracking and getting scrambled.</p><p>Rovelli says key aspects of time are described by the second law of thermodynamics, which states that heat always passes from hot to cold. This is a one-way street. For example, an ice cube melts into a hot cup of tea, never the reverse. Rovelli suggests a similar phenomenon might explain why we're only able to perceive the past and not the future.</p><p style="margin-left: 20px;">"Any time the future is definitely distinguishable from the past, there is something like heat involved," Rovelli wrote for the <a href="https://www.ft.com/content/ce6ef7b8-429a-11e8-93cf-67ac3a6482fd" target="_blank"><em>Financial Times</em></a>. "Thermodynamics traces the direction of time to something called the 'low entropy of the past', a still mysterious phenomenon on which discussions rage."</p>
The strange subjectivity of time<p>Time moves differently atop a mountain than it does on a beach. But you don't need to travel any distance at all to experience strange distortions in your perception of time. In moments of life-or-death fear, for example, your brain would release large amounts of adrenaline, which would speed up your internal clock, causing you to perceive the outside world as moving slowly.<br></p><p>Another common distortion occurs when we focus our attention in particular ways.</p><p style="margin-left: 20px;">"If you're thinking about how time is <em>currently</em> passing by, the biggest factor influencing your time perception is attention," Aaron Sackett, associate professor of marketing at the University of St. Thomas, told <em><a href="https://gizmodo.com/why-does-time-slow-down-and-speed-up-1840133782" target="_blank">Gizmodo</a></em>.<em> "</em>The more attention you give to the passage of time, the slower it tends to go. As you become distracted from time's passing—perhaps by something interesting happening nearby, or a good daydreaming session—you're more likely to lose track of time, giving you the feeling that it's slipping by more quickly than before. "Time flies when you're having fun," they say, but really, it's more like "time flies when you're thinking about other things." That's why time will also often fly by when you're definitely <em>not</em> having fun—like when you're having a heated argument or are terrified about an upcoming presentation."</p><p>One of the most mysterious ways people experience time-perception distortions is through psychedelic drugs. In an interview with <a href="https://www.theguardian.com/books/2018/apr/14/carlo-rovelli-exploding-commonsense-notions-order-of-time-interview" target="_blank"><em>The Guardian</em></a>, Rovelli described a time he experimented with LSD.</p><p style="margin-left: 20px;">"It was an extraordinarily strong experience that touched me also intellectually," he said. "Among the strange phenomena was the sense of time stopping. Things were happening in my mind but the clock was not going ahead; the flow of time was not passing any more. It was a total subversion of the structure of reality."<br></p><p>It seems few scientists or philosophers believe time is completely an illusion.</p><p style="margin-left: 20px;">"What we call <em>time</em> is a rich, stratified concept; it has many layers," Rovelli told <em><a href="https://physicstoday.scitation.org/do/10.1063/PT.6.4.20190219a/full/" target="_blank">Physics Today</a>.</em> "Some of time's layers apply only at limited scales within limited domains. This does not make them illusions."</p>What <em>is</em> an illusion is the idea that time flows at an absolute rate. The river of time might be flowing forever forward, but it moves at different speeds, between people, and even within your own mind.
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Controversial physics theory says reality around us behaves like a computer neural network.
- Physicist proposes that the universe behaves like an artificial neural network.
- The scientist's new paper seeks to reconcile classical physics and quantum mechanics.
- The theory claims that natural selection produces both atoms and "observers".
Vanchurin interview:<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="539759cbfd8fcd5b6ebf14a3b597b3f9"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/bmyRy2-UhEE?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Vanchurin on “Hidden Phenomena”:<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="18886ffd5e5840bb19d4494212f88d82"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/2NDVdNwsHCo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>Vitaly Vanchurin speaking at the 6th International FQXi Conference, "Mind Matters: Intelligence and Agency in the Physical World." The Foundational Questions...
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