- 3097 - ASTEROIDS - start life on Earth? - When the Earth was first formed in he solar System with the other planets it was pummeled by asteroids. Thousands of these space rocks slammed into the young Earth, sometimes with a force powerful enough to vaporize the seas.
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- These asteroids came primarily from the asteroid belt, which was perturbed by the evolving orbits of the Solar System’s larger planets. The evidence of this assault can be seen in the pockmarked surface of the Moon, which also failed to escape the onslaught of asteroid impacts
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- Not long after asteroids stopped raining down, something incredible happened on Earth. Locked in our planet's geological record from the time, is the earliest evidence of life on Earth. For millennia, scientists and philosophers have searched for the answer to the question: Where did life come from?
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- There are several leading theories of the origin of life on Earth. And one has to do with this violent astronomical era from our planet's past: “The Impact-Origin of Life Hypothesis?”
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- The theory is founded on the idea that the cataclysmic assault on the early Earth may have actually been the catalyst necessary to bring life into existence.
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- Essentially, the force of the asteroids slamming into the Earth would cause the formation of new hydrothermal systems all over the planet. These systems would provide both the venue and the necessary chemistry for life to arise.
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- The very same impact events that made conditions at the surface completely untenable for life, at the same time were constructing these vast subsurface hydrothermal systems. While asteroids made Earth's surface unlivable, they were making its subsurface a hotbed of creation.
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- Genetic analysis of modern organisms led prominent origins of life researchers to suggest that the earliest life forms on Earth were “thermophiles“, microbes that thrive in very hot environments.
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- Early life could have evolved in the subterranean hydrothermal systems where water would be stable and the fledgling organisms would be protected from hostile surface conditions.
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- The original RNA studies identified thermophiles as early organisms that subsequent genetic analysis has strengthened this original claim.
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- Life is thought to have evolved from “prebiotic chemistry“, the formation of precursor molecules from geological and other passive, non-living processes. At some point, these primitive chemical systems would have had to make the leap to “biochemistry“.
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- But many of the chemical reactions that modern life utilizes are not thermodynamically favorable. Essentially, they require extra energy to complete. One of the ways they solve that problem is when comets hit the Earth, they release a ton of energy. And that energy can go into rearranging molecules into higher energy states.
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- One of the problems with proving this theory is that the actual craters from the early Earth's days of constant bombardment are long gone, erased by subsequent geological forces.
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- Instead, some of the best evidence, surprisingly, may be preserved in the Chicxulub crater. Chicxulub, located underneath the northern edge of the Yucatan Peninsula in Mexico, is the impact crater left by the meteor blamed for the death of the dinosaurs 66,000,000 years ago. It is one of the best preserved impact craters on Earth.
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- Recently scientists discovered evidence of an ancient sulfate metabolizing microbial ecosystem that lived in what was once a hydrothermal system beneath the Chicxulub crater. While the impact is much more recent than any that might have catalyzed life on Earth, it can be used for studying the geological and biological ramifications of the early Earth asteroid bombardment.
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- Scientists are looking for evidence of different kinds of ancient microbes at Chicxulub. Additional lab-based experiments could also help determine if the chemical environments in impact-generated hydrothermal systems could lead to life or biological precursor molecules,.
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- Other possible venues for the origin of life on Earth have also been proposed. These include:
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------------------- Deep-sea hydrothermal vents: An attractive prospect for scientists, saltwater reactions create a unique chemical environment that could foster biology springing from chemistry.
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------------------ Volcanism: This can generate similar activity to that of the hydrothermal systems created by asteroid impacts.
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------------------ Darwin’s original “warm little pond” theory. An area that goes through wet-dry cycles, like a shoreline of a pond, may have helped facilitate the beginning of life.
Researchers have found that exposing simple biomolecules to wet-dry cycles in the lab allows them to form larger, more complex molecules necessary for life.
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-------------------- Impact-generated hydrothermal systems could also produce alternating wet-dry conditions. ------------------------ Other reviews available about asteroids:
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- 3091 - ASTEROID - near miss and a perfect hit? One of the larger stones that hit was about 5 centimeters long. Its crust is the remainder of the surface that got heated as the meteorite came through the atmosphere. “Winchcombe meteorite” may look a bit like a broken barbecue briquette, but to scientists, it is absolutely beautiful.
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- 2948 - ASTEROID - touch down on Bennu asteroid? OSIRIS-REx launched into space in 2016 and reached the asteroid Bennu two years later. In the time since, the spacecraft has set records for orbiting the smallest object yet for a spacecraft, and in the tightest orbit to boot.
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- 2939 - ASTEROID - sample return? - Japan’s Hayabusa 2 probe zoomed past Earth on December 5th and dropped off a capsule containing bits of an asteroid, finishing a six-year round trip to an asteroid
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- 2916 - ASTEROID - near miss? Many nearby stars will pass close to the Oort Cloud at the outskirts of our Solar System, but only one will move through it. In about 1.35 million years, Gliese 710 likely will gravitationally perturb millions of comets, sending a sizable number on a potential collision course with Earth.
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- 2910 - ASTEROID - mining gold from asteroids? “16 Psyche” is an asteroid full of metal in the asteroid belt that could be worth $700 quintillion.. NASA plans to visit 16 Psyche by 2026. Could we be commercial mining faraway asteroids or should we start with the moon?
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- 2722 - SPACETIME - at the macro and micro levels.? How Can Space and Time be Related?. Space and time seem to be absolute quantities to us. It is hard to see their interrelationship until you take their ratio as velocity and extend that ratio to its limits. Velocity is space / time!
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- 2627 - ASTEROID - to hit Mother Earth. It is not an if, it is a when. Astronomers are tracking Near Earth Asteroids, NEAs. There are many, and each one needs to be identified with an orbit trajectory to learn if it will be a threat. OK, let’s just say they see one coming right at us. What then?
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- 2595 - ASTEROID - Teacher’s Lesson Plan. The fastest spinning asteroid was discovered by an amateur astronomer, but using a professional telescope by remote control. This just became available to all teachers who want to teach some astronomy using the internet.
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- 2332 - Asteroids, comets, and meteors are ice balls and rocks orbiting the Sun just like our planet. What we call these objects all depends on where the debris was formed in the accretion disk that rotated around the Sun when the planets were formed.
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- 2314 - On December 18, 2018, an asteroid barreled through the atmosphere at a speed of 72,000 miles per hour , on a steep trajectory of seven degrees. Measuring several meters in size, the space rock exploded 16 miles above the Earth's surface, with an impact energy of 173 kilotons.
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- 2296 - Asteroids are small, airless rocky worlds revolving around the sun that are too small to be called planets. They are also known as planetoids or minor planets. In total, the mass of all the asteroids is less than that of Earth's moon. But despite their size, asteroids can be dangerous.
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- 2250 - Asteroids visits and impacts. We have several spacecrafts visiting asteroids right now. January, 2019. This Review will summarize the current visits and then get into the history even some that are evident on the Earth and on the Moon.
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- 2226 Asteroid Ryugu. Spacecraft landed on the surface on September 2018. What have we learned? The Japanese spacecraft is studying the asteroid named Ryugu. After over a 3 year journey the spacecraft has released rovers to the surface to make measurements. For the next 18 months, the spacecraft will probe, poke, prod and impact the asteroid, deploying the small lander and three rovers to hop along the surface.
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- 2209 Asteroid Oumuamua from another solar system. If Oumuamua came from an extrasolar planetary system like our solar system, it is much more likely to have begun its journey as a comet. The ejection of an asteroid from an extrasolar system is much less likely and could involve a violent event such as the explosion of a star.
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- 2203 Asteroid Bennu. Arrived December 2019 and will inspect every square inch of the asteroid before returning home in 2023.
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- 2044 - Oumuamua is a needle shaped asteroid that will exit solar system. This Review lists 15 other reviews about asteroids.
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- 1924 - Visitors from outer space. Asteroids and supernovae affect life on Earth. Detective work is looking at the evidence. Did the asteroid that struck the Yucatan Peninsula kill off the dinosaurs? Did supernova 1987 affect life on Earth?
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- 1923 - In 2017 50 asteroids passed us at a distance closer than our Moon. When will a big asteroid hit the Earth? What is the mission that will land a spacecraft on an asteroid and bring back a sample of its surface? This mission to also to determine the likelihood of it impacting Earth. It comes by every 6 years.
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- 1871 - Asteroids and their Trojan orbits. In order to predict asteroids trajectories we need to learn about their composition. Missions will soon visit two asteroids to learn more. Maybe, where life originated.
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- March 19, 2021 ASTEROIDS - start life on Earth? 3097
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