A young planet neighboring Earth was destroyed before it finished forming and now we have found a piece in the Sahara

According to estimates based on the fireball tracking, is calculated Approximately 17,000 meteorites fall to Earth per year. Only a few of them recover. There are about 80,000 registered worldwide. However, the numbers must be much higher. There will be a multitude of meteorites abandoned in drawers or lost as simple unidentified stones that would make that figure much higher. It’s a shame, because a single meteorite can give us very useful information about our planet and its neighbors.

A good example of this is NWA 12774, a fragment found in 2019 in the Sahara. Thanks to it, a team of scientists from the University of Colorado Boulder has managed to extract very interesting data about the dawn of the Solar System.

The reconstructed history. The analysis The composition of this meteorite, as well as computer simulations, have allowed us to establish that it must be a fragment of a protoplanet of a size similar to the Moon or Mars, which 4.5 billion years ago decomposed into debris, possibly after colliding with another celestial object while rotating around the Sun.

An especially rare angrita. Initial analysis of this meteorite indicated that it is an angrite. This is a very rare type of rock among meteorites. In fact, it is estimated that of the 80,000 that have been registered, only 68 are Angritas. They are rare meteorites because they contain very little silica, a material that is very abundant on rocky planets like Earth.

Initially, angritas were thought to be asteroid fragments. However, in this case it is doubly rare, because it also contains clinopyroxene, a very common crystal in the Earth’s crust and mantle. As if that were not enough, said clinopyroxene is rich in CaTs forms, a “version” of this mineral in which one magnesium atom and one silicon atom are replaced by two aluminum atoms. It is a process that requires very high pressure conditions to occur.

A large origin. According to the computational reconstructions that have been carried out, to generate such a quantity of CaTs it would be necessary for this object to be subjected to a pressure of 17.5 kilobars. It is something immense. To give us an idea, in the depths of the Mariana Trench barely reaches one kilobar. This pressure could not originate inside an asteroid. According to the calculations made by these scientists, an object of at least 2,000 kilometers in diameter would be needed.

Even more. Another relevant fact about this meteorite is that it has sharp edges and chemical patterns that would have been erased if it had originated at a great depth within its parent body. This tells us that said body is immense, since what is relatively shallow compared to its size is actually great depth in terms of pressure. Therefore, the 2,000 kilometers would be short. We would rather be looking at about 3,600 kilometers in diameter, approximately that of the Moon. Some estimates would point to something even larger, like Mars, but in principle they fit the dimensions of the Moon.

Very different from Earth. Protoplanets are planets in birth. They must continue colliding and fusing material around them to finish becoming planets. The object that originated this meteorite did not do so. But it should have been part of the dawn of the Solar System. Thanks to him, we know that, at first, the composition of rocky planets would be very different from that of Earth. Something must have changed over time. It would be ideal to analyze more meteorites, since there must be others like NWA 12774. The problem is that we will have to dust off those abandoned drawers to find them.

Image | John Kashuba

In Xataka | We have been trying to answer the question “where do meteorites come from” for years. And it’s harder than it seems