Near-Earth objects and close calls
- Thread starter Gawan
- Start date
Pretty impressive fireball in Leningrad oblast, Russia, 11-11-2021 17:38 local time, caught on multiple cameras.
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Russia blew up a satellite with their new anti-satellite system, and now the space station has to be evacuated for a debris threat. The satellite they blew up was launched in the early 80's and weighed 2,000 pounds, and shares a very close orbit with the ISS.
www.thedrive.com
Russian Anti-Satellite Test Produces Dangerous Debris Cloud In Orbit (Updated)
U.S. Space Command has confirmed a "debris-generating event," which now presents a potential risk to the International Space Station.
Another bright fireball captured on dashcams in Russia, today, 17th November:
A strange anomaly has been discovered in New Mexico, and behind it lies an even greater discovery
Scientists have discovered an unusual magnetic anomaly in the American state of New Mexico, not far from Santa Fe. The magnetism at that point was 10 times weaker than usual. And that led them to a much bigger discovery - how to find the places where meteorites hit, which are hidden.
Meteorite impact sites are seemingly easy to find, as they leave craters in the earth's surface. However, this is not always the case. Sometimes the places of impact are hidden by layers of dust, earth and vegetation over time. Now, thanks to a magnetic anomaly in New Mexico , scientists have found a way to discover them.
The magnetism at the point of impact is 10 times smaller
Meteors enter the Earth's atmosphere at speeds of up to 72 kilometers per second , but slow down as they pass through it due to friction with the layers of the atmosphere. Thus is produced the bright light that we see in the sky when the meteorite becomes meteoroid (meteor into the atmosphere). Due to that friction, some of the meteorites burn up, while some shrink and hit the Earth's surface , becoming meteorites.
During the impact, a crater is created , but also other geological processes, such as high temperatures, high pressure, ejection of particles at high speed, all at the same time, writes "Science Alert".
During the collision, plasma is created , in which atoms are broken into electrons and positive ions.
"When a collision happens, it's a huge speed. That speed causes kinetic energy to be converted into heat, vapors and plasma, " said geologist Guenter Kletecka of the University of Alaska Fairbanks.
Scientists in New Mexico discovered that the plasma changed the magnetism of the rocks at the point of impact in a strange way , and that because of that it was 10 times weaker than usual, according to a scientific paper published in the scientific journal "Syantificate Report".
A rock structure indicating a meteorite impact near Santa Fe in the Sangre de Cristo Mountains
CC BY-SA 3.0 / Wikipedia / Ikluft /
Traces of magnetic metals in the sediments during geological history aligned with the lines of the Earth's magnetic field and thus remained trapped in the rocks. This is a very low rate of magnetism , which can only be measured with special geological equipment.
Plasma made a "magnetic shield"
When a shock wave occurs, such as a meteorite impact , the magnetism of the rock decreases, because the magnetized parts of the rock take over a good part of the energy shock.
"The shock wave produces more energy than the energy that retains magnetization in individual magnetic particles," the scientists state in their paper.
It is common for rocks to regain their level of magnetization after the shock wave has passed, but at the site of the impact, which is estimated to be 1.2 billion years old , near Santa Fe, not far from Route 475 in the Sangre de Cristo Mountains, magnetism has never returned.
Scientists believe that the plasma has made a "magnetic shield" that keeps the magnetized particles in such a state that they cannot align with the Earth's magnetic field, so the magnetization is 10 times less than usual.
This discovery could help scientists discover other places where meteorites hit, where the plasma could have caused a similar effect, although there are no clear traces on the Earth's surface that the impact occurred.
(auto-translation with Google)