The role of the sun during solar system formation

The strange oxygen atom mixture in an exploded meteorite in the sky of Pueblito de Allende, Mexico nearly 40 million years ago has caused scientists to suffer since that time.

Tiny mineral deposits on the meteorite surface are thought to be from the solar system. They contain the forms of oxygen, also known as isotopes, which are very different from the oxygen isotopes detected in rock on known planets; including Earth, the moon and meteorites from Mars.

Now, the researchers at the University of California San Diego, along with the Lawrence Berkeley National Laboratory, have developed a model that can explain this unusualness: the idea that light from the early Sun formed probably changed the equilibrium of isotopes in the molecules formed after the sun shines. When the researchers shone light on the carbon mono-oxide gas to produce carbon dioxide, the equilibrium of oxygen isotopes in the new molecule did not change according to the predicted path through the model that the scientists Study published on September 5 issue in Science.

Mark Thiemens, head of the Department of Material Science and professor of chemistry and biochemistry at the University of California - San Diego and project manager, said: 'We have understood a little bit about the process. solar system ' . The results gradually eliminate the possible hypothesis of condensed gas and dust processes to form planets; thereby helping the team and scientists find information about the solar wind that NASA's Genesis spacecraft brought.

Atomic shield

Scientists think that the early Sun releases extremely strong ultraviolet rays. Ultra-short light energy will knock off oxygen atoms in some molecules so they are free to cling to other atoms to form a new complex. In the process, oxygen atoms absorb energy.

This is the way that gas becomes dust and forms minerals of larger sizes, colliding with each other to continue forming the planet. Oxygen is the most abundant chemical element in the solar system. It is also a substance involved in most of the above activities.

Each oxygen isotope reacts to a certain set of light wavelengths. So the cloud of monkey molecules contains a lot of oxygen isotopes that will turn off light, protecting gas molecules when light passes through. Other wavelengths of light, including wavelengths that can turn on the oxygen isotope, will not be hindered to allow more rare isotopes to exist in new molecules.

The most abundant isotope of oxygen is the oxygen isotope. 16. Soil and rock on planets have relatively much heavier isotopes, more rarely it seems that these rare isotopes are preferred when the planet is formed.

Photoelectric effect

Subrata Chakraborty, a postdoctoral researcher at the University of California San Diego and the first author of the study, said: 'We decided to directly test the notion that photovoltaic shields could be replaced. change the ratio of isotopes' . The team fired a powerful long-wavelength ultraviolet ray created by the Lawrence Barkeley National Laboratory of Light in a tube filled with carbon mono-oxide gas. Light has released some oxygen atoms, allowing them to reunite with other carbon monoxide molecules to form carbon dioxide. Chakraborty then collected and analyzed carbon dioxide to determine the equilibrium of oxygen isotopes in new molecules.

By precisely controlling the wavelength of light, scientists were able to create an environment that forms the oxygen isotope mixture like the environment on Earth or Allende meteorite.

The wavelength of light that is absorbed by the oxygen isotope 16 produces carbon dioxide molecules that contain more severe forms of oxygen. The scientists only conducted experiments with two wavelengths of light: a wavelength that produced a mixture of heavy oxygen isotopes, the remaining wavelengths did not.

The wavelength of light that is not absorbed by the 16 isotope oxygen will produce a mixture of the Alllende meteorite mixture. Again half of the two wavelengths of the light that were tested, one wavelength that created the mixture, the remaining wavelength did not. Chakraborty said: 'Some processes can alter the mixture, but not the photovoltaic shield'.

Original mix

According to Thiemens, the specimens brought by the GENESIS spacecraft will likely have to be analyzed based on the results of this study. By analyzing the outside atmosphere of the sun through the solar wind, the study aims to determine the initial composition of the solar nebula, as well as the dust gas vortex that forms the solar system. Calculations made by Thiemen's team and other scientists will help solve the incompatible chemical link between meteorites and rock on planets. Several research models have also been set up to explain unusual characteristics, including the view that an exploding star can explode with an enormous amount of oxygen isotopes. will be removed when the evidence demonstrates that they are unlikely to exist.

According to Thiemens, the only hypothesis that survives is the idea of ​​molecular symmetry. This view suggests that an atom with two oxygen isotopes on either side can become a stable molecule if two isotopes are not matched. This process also supports the formation of molecules containing more rare oxygen isotopes.

Thiemens said: 'There is no strong activity. There is no need for the existence of an exploding star to create nebula-sized clouds in the universe. '

Musahid Ahmed of Lawrence Berkely National Laboratory and Teresa Jackson of California San Diego University are co-authors of the study. NASA and the Department of Energy funded the project.

The faint spots on the meteorite surface are the oldest minerals in the solar system.Recombinant oxygen atoms in these minerals have led scientists to suffer for decades.(Photo: Susan Brown)