- Tram Ho
Science has successfully confirmed what is the oldest hard matter on Earth, but the surprise has not stopped there: it is “older” than our Solar System, a few hundred years older. million years. New research indicates that this microscopic-sized cosmic dust formed at some distant star some 5 to 7 billion years ago; Our Sun is “only” 4.6 billion years old.
Then some meteorite brought this dust to Earth, so we can make new discoveries and articles today.
” This is one of the most interesting studies I’ve ever done, ” said cosmologist chemist Philipp Heck, who works at the Museum of Natural History and University of Chicago. ” This is the oldest solid material ever discovered, and they tell us a lot about how stars in the galaxy we live are .”
Despite the precedent of meteorites containing a bit more matter than the Solar System, they are still very rare and very difficult to determine their existence, because these particles are very small, hidden deep inside. the stone “fell from the sky”. Murchison meteorite, for example, weighs more than 100 kg, spilling out from a meteor explosion in the skies of Murchison, Australia in September 1969.
Murchison meteorite is located in the museum.
The Natural History Museum has taken 52 kg of meteorites and put a lot of effort into studying them. They discovered a large amount of silicon carbide minerals – confirmed to have come from another star. The time it takes from another star to here is longer than the age of the Solar System, so scientists know that this material is very old, but they have not been able to measure its exact age .
Since the 1990s, researchers have been extracting silicon carbide powders from meteorites, by crushing stones out and reducing unwanted silicates with acids. At that time, the analysis tool of silicon carbide powder was not as modern as it is now, until science waited to be advanced enough to answer the questions that researchers had been suffering for so long.
They use electron microscopes to scan, measure mass of secondary ions and rare gases, look for the effect of cosmic radiation, which can penetrate solid objects (such as meteorites) and Impact on silicon carbide.
“ Cosmic rays can interact with matter to form a new element. And the longer they are exposed to radiation, the more elements are formed , ”Mr. Heck explained. “ I often take an example of putting a bucket outside the storm. If it rains continuously, the amount of water collected in the bucket will reflect the amount of time the bucket is outside . ”
By detecting the existence of helium-3 and neon-21 isotopes in silicon carbide powders, scientists determined their lifetime. Some samples reach 5.5 billion years old, but most silicon carbide specimens are only aged between 4.6 and 4.9 billion years.
It is the “younger” silicon carbide powder that excites scientists: they tell us the historical story of the Milky Way.
“ Our hypothesis is that most of this powder, dating from 4.6 to 4.9 billion years old, appeared during a star formation. At the time before the Solar System was born, more stars were born than usual, ”explains Professor Heck.
This sequence of star formation occurred about 7 billion years ago. Then as the star gets older, these silicon carbide materials will flow into streams and flow into the Universe; Over time, they will coalesce with many other matter to become meteorites, like what happened to Murchison meteorite.
According to Professor Heck, the discovery of this ancient matter encapsulated in a meteorite indicates that the process of star formation in the Universe is very volatile.
“ Many people think that the rate of stars forming in the galaxy is a constant. But thanks to the existence of this matter, we have direct evidence that about 7 billion years ago, there was time for stars to form at a much faster rate than normal. This is a key discovery in our research , ”said Heck.
The feeling of holding on to a dough handle that is even older than our Solar System is amazing.
Refer to Science Alert
Source : Genk