- 3541 - ASTEROID - Moon and Earth impacts? Asteroid impacts have been discovered on the moon and on the Earth. Most recent research has determined that some are coming from outside our galaxy.
--------------------- 3541 - ASTEROID - Moon and Earth impacts?
- One side of the moon is littered with far more craters than the other, and researchers finally know why: A massive asteroid that slammed into the moon around 4.3 billion years ago wreaked havoc in the moon's mantle on both sides.
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- More than 9,000 visible craters pockmark the moon due to barrage of impacts from meteors, asteroids and comets over billions of years. However, these craters are not evenly distributed across the lunar surface.
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- The far side of the moon, which people never see from Earth because the moon is tidally locked, meaning that it takes the same amount of time for the moon to rotate and orbit Earth, has a considerably higher concentration of craters than the visible nearside.
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- The nearside of the moon has fewer pits because the surface is covered in lunar maria which are vast stretches of solid lava that we can see with the naked eye on Earth as dark patches on the moon. These lava fields likely covered up the craters that would otherwise have marked the moon's nearside. The far side of the moon has almost no lunar maria, which is why its craters are still visible.
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- Scientists have long suspected that lunar maria formed in the wake of a massive collision around 4.3 billion years ago. This collision created the South Pole Aitken basin (SPA), a huge crater with a maximum width of around 1,600 miles and a maximum depth of 5.1 miles, which is the largest pit on the moon and the second largest confirmed impact crater in the solar system. Until now researchers were unable to explain why only the nearside of the moon has lava fields.
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- The big impacts like the one that formed SPA would create a lot of heat. The dark regions on the moon that are visible from Earth are the solid lava flows which cover many of the nearside's craters.
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- Researchers already knew the nearside's lava fields originated within the moon's mantle, because lunar samples brought back by the Apollo missions contained radioactive, heat-generating elements such as potassium, phosphorus and thorium that are all suspected to be found in abundance within the lunar mantle.
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- Computer simulations revealed that the SPA impact would have created a heat plume within the mantle that pushed the radioactive elements toward the crust. The researchers repeated the simulation for a number of possible scenarios of the SPA impact, including direct hits and glancing blows, and found that regardless of how the asteroid hit, the mantle impacts would have only affected the nearside of the moon.
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- When a space rock collided with the moon, it caused lava from the mantle to pour out on the nearside, burying many of its older impact craters. It ends up concentrating these heat-producing elements on the nearside. This contributed to the mantle melting that produced the lava flows we see on the surface.
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- Back here on Earth a fireball blazed through the skies over Papua New Guinea in 2014 that was actually a fast-moving object from another star system. A small meteorite measuring just 1.5 feet across, slammed into Earth's atmosphere on January 8, 2014, after traveling through space at more than 130,000 mph. This speed far exceeds the average velocity of meteors that orbit within the solar system.
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- A 2019 study argued that the meteor's speed, along with the trajectory of its orbit, proved with 99% certainty that the object had originated far beyond our solar system, possibly from the deep interior of a planetary system or a star in the thick disk of the Milky Way galaxy.
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- This 2014 meteor the first interstellar object ever detected in our solar system, the memo added. The object's detection predates the discovery of “'Oumuamua“, cigar-shaped object that is also moving far too fast to have originated in our solar system by three years. Unlike the 2014 meteor, 'Oumuamua was detected far from Earth and is already speeding out of the solar system.
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- Because the meteorite ignited over the South Pacific Ocean, it's possible that shards of the object landed in the water and have since nestled on the seafloor. The possibility of recovering the first piece of interstellar material is worth searching for. An announcement will be made shortly???
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April 12, 2022 ASTEROID - Moon and Earth impacts? 3541
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