The discovery of a rare meteorite, Northwest Africa (NWA) 12774, has revealed a lost moon-sized world from the dawn of the solar system. This finding has significant implications for our understanding of planetary evolution, challenging existing theories and offering a new perspective on how planets formed. Personally, I find this discovery particularly fascinating as it provides direct evidence of a protoplanet, a long-lost world that once orbited the young Sun. What makes this finding even more intriguing is the composition of the meteorite, an angrite, which is among the oldest volcanic rocks in the solar system. These meteorites are extremely rare, with only 68 known examples out of over 80,000 found on Earth. The unusual composition of angrites, with very little silicon dioxide, has long puzzled scientists. They had assumed these meteorites originated from small asteroids, but the discovery of high levels of aluminum in the clinopyroxene mineral within NWA 12774 suggests otherwise. The extreme pressure required to form this mineral deep within a larger body indicates that the parent body of the angrites must have had a radius of at least 1,000 kilometers, comparable to the Moon. This finding raises a deeper question: what happened to this ancient world? One possibility is that it was destroyed during a major collision in the chaotic early solar system, and its fragments may have become part of other rocky planets, including Earth. This discovery points to a distinct and separate evolutionary path in planetary formation, fundamentally different from the ingredients of Earth and Mars. In my opinion, this finding is a significant step forward in our understanding of planetary evolution, offering a new perspective on how planets formed and evolved in the early history of our solar system. It also highlights the importance of thorough study of meteorites, as there may be more protoplanets waiting to be discovered. The implications of this discovery are far-reaching, and it will be interesting to see how it shapes our understanding of planetary science in the future.
