The Ec 002 Meteorite: Oldest Known Example Of Magma From Space Is 4.6 Billion Years Old

[mn90403]

There are thousands of meteorites discovered all over the world.  Some areas preserve meteorites better than others.  The oceans for instance degrade most of them and other climates make it nearly impossible to find them.  When they are found they are studied and classified.

This meteorite was:

A lonely meteorite that landed in the Sahara Desert in 2020 is older than Earth. The primeval space rock is about 4.6 billion years old, and is the oldest known example of magma from space.

This meteorite is an achondrite, a type of meteorite that comes from a parent body with a distinct crust and core, and lacks round mineral grains called chondrules, according to the Center for Meteorite Studies at Arizona State University.

https://www.livescience.com/meteorite-asteroid-early-solar-system.html  

[GB_Amateur]

Where are all the protoplanets with andesite crusts today? During our solar system's volatile period of planetary birth, most of these protoplanets likely didn't make it past infancy, according to the study. Either they were smashed to bits in collisions with other rocky bodies, or they were absorbed by bigger and more successful rocky planets, such as Earth, Mars, Venus and Mercury, leaving few traces behind to spawn meteorites such as EC 002.  (cut and pasted from the article Mithel linked.)

Now there's a scientific term:  smashed to bits!! 

They didn't mention the moon but I wonder if that environment (and lower gravitational potential) would be more conducive for these types of meteorites to have survived.  Hopefully the supposed return to the moon by humans will include considerable scientific investigation, even more than the Apollo missions.  Metal detecting on the moon, anyone?

[Lunk]

10 hours ago, GB_Amateur said:

They didn't mention the moon but I wonder if that environment (and lower gravitational potential) would be more conducive for these types of meteorites to have survived.

If you think about it, the moon is actually less hospitable to the survival of impactors than the earth is. Since the moon has no atmosphere, there is no mechanism to slow or stop a meteoroid from slamming into the moon at cosmic velocity, which can be as high as 160,000 mph. At this velocity, a meteoroid with a mass of only 1 kilogram (2.2 lbs) would have the kinetic energy equivalent of over a half a ton of TNT; more than enough to pulverize, if not vaporize, the object on impact. Besides, even if it were to survive, it would be unrecognizable as a meteorite, since no atmosphere means no ablation and therefore no fusion crust, regmaglypts or flow features of any kind. But I would still like to metal detect on the moon, because you know there has to be gold and other metals up there!😁

Here's a cool little article on meteorite formation, from the American Meteor Society website:

Meteoroids enter the earth’s atmosphere at very high speeds, ranging from 11 km/sec to 72 km/sec (25,000 mph to 160,000 mph). However, similar to firing a bullet into water, the meteoroid will rapidly decelerate as it penetrates into increasingly denser portions of the atmosphere. This is especially true in the lower layers, since 90 % of the earth’s atmospheric mass lies below 12 km (7 miles / 39,000 ft) of height.

At the same time, the meteoroid will also rapidly lose mass due to ablation. In this process, the outer layer of the meteoroid is continuously vaporized and stripped away due to high speed collision with air molecules. Particles from dust size to a few kilograms mass are usually completely consumed in the atmosphere.

Due to atmospheric drag, most meteorites, ranging from a few kilograms up to about 8 tons (7,000 kg), will lose all of their cosmic velocity while still several miles up. At that point, called the retardation point, the meteorite begins to accelerate again, under the influence of the Earth’s gravity, at the familiar 9.8 meters per second squared. The meteorite then quickly reaches its terminal velocity of 200 to 400 miles per hour (90 to 180 meters per second). The terminal velocity occurs at the point where the acceleration due to gravity is exactly offset by the deceleration due to atmospheric drag.

Meteoroids of more than about 10 tons (9,000 kg) will retain a portion of their original speed, or cosmic velocity, all the way to the surface. A 10-ton meteroid entering the Earth’s atmosphere perpendicular to the surface will retain about 6% of its cosmic velocity on arrival at the surface. For example, if the meteoroid started at 25 miles per second (40 km/s) it would (if it survived its atmospheric passage intact) arrive at the surface still moving at 1.5 miles per second (2.4 km/s), packing (after considerable mass loss due to ablation) some 13 gigajoules of kinetic energy.

On the very large end of the scale, a meteoroid of 1000 tons (9 x 10^5 kg) would retain about 70% of its cosmic velocity, and bodies of over 100,000 tons or so will cut through the atmosphere as if it were not even there. Luckily, such events are extraordinarily rare.

All this speed in atmospheric flight puts great pressure on the body of a meteoroid. Larger meteoroids, particularly the stone variety, tend to break up between 7 and 17 miles (11 to 27 km) above the surface due to the forces induced by atmospheric drag, and perhaps also due to thermal stress. A meteoroid which disintegrates tends to immediately lose the balance of its cosmic velocity because of the lessened momentum of the remaining fragments. The fragments then fall on ballistic paths, arcing steeply toward the earth. The fragments will strike the earth in a roughly elliptical pattern (called a distribution, or dispersion ellipse) a few miles long, with the major axis of the ellipse being oriented in the same direction as the original track of the meteoroid. The larger fragments, because of their greater momentum, tend to impact further down the ellipse than the smaller ones. These types of falls account for the “showers of stones” that have been occasionally recorded in history. Additionally, if one meteorite is found in a particular area, the chances are favorable for there being others as well.

 

[GB_Amateur]

1 hour ago, Lunk said:

...Bodies of over 100,000 tons or so will cut through the atmosphere as if it were not even there. Luckily, such events are extraordinarily rare.  (Emphasis mine.)

Now there's an understatement if I ever heard one!  (Just ask a Late Cretaceous dinosaur....  Oh, wait, they wouldn't understand our modern language.  Nevermind.)