The traces of the most ancient on this point of matter in the Solar system was discovered in one of the fragments of the meteorite Mercantile. Cosmic dust about seven billion years.
The meteorite fell in 1969 in South Australia near the village of Murchison, in whose honor and named the celestial body.
“We can say that we hold in our hands the fossilized remains of stars. These particles of Stardust were inside a meteorite billions of years ago. This made them perfect time capsules, in which are preserved traces of an era that ended before the birth of the Solar system”, – told associate Professor, University of Chicago Philipp heck, who participated in the study.
Heck and his colleagues became interested in the grains of silicon carbide, high-melting compounds of carbon and silicon, which are components of the meteorite. Scientists measured their age, based on the ratio of shares of neon-21 and helium-3. Experts smashed dozens of large grains of interstellar matter, let them through the particle accelerator and precisely calculated their share.
It turned out that most of them have formed about 4.6-4.9 billion years ago. This suggests that before the emergence of the Solar system was a powerful flash of star formation in the neighborhood with the “germ” of our star. The same event occurred about seven billion years ago.
“Previously it was thought that stars formed in the milky Way with approximately constant speed. Thanks to this meteorite and the dust grains, we have obtained the first direct evidence that this was not the case. Seven billion years ago, in the galaxy, an event occurred which accelerated the formation of new bodies”, – said the heck.