The materials that make up the Earth come from the giant red star dust

Researchers at the Swiss Federal Institute of Technology (ETH) believe that a portion of the material that makes up Earth comes from giant red stars. They also know why the Earth contains more star dust than asteroids or Mars - objects farther away from the Sun.

Mixture of salt and pepper

About 4.5 billion years ago, collapsing dust clouds and interstellar gas occurred. In the center of the cloud appeared the Sun. Around the Sun begins to form gas - dust disks; thereby forming the Earth and other planets.

Giant red star.

That interstellar material mixture also contains foreign particles. 'These are dust particles formed in the vicinity of other stars' , explained Professor Maria Schonbachler at the Swiss Federal Institute of Technology.

These dust particles occupy a small proportion in the dust cloud and disperse unevenly in the gas-dust disk.'This dust reminds us of a salt and pepper mixture,' says Maria Schonbachler. During formation, the planets have different chemical composition.

Thanks to exceptionally accurate measurement technology, scientists can detect stellar dust from the time of the Solar System's formation in neighboring Earth. Scientists look for specific elements in the stellar dust and study the isotopic richness of those elements.

'The change in the proportion of these isotopes is typical traces,' said Ms. Schonbachler.

For the past 10 years, scientists have been studying rock samples from Earth and meteorites. They also found isotopic abnormalities of many elements. Schonbachler and her research team analyzed the stalagmites that were once part of the core of asteroid that had been destroyed.

They focused on finding traces of the palladium element (Pd) . Other research groups have done similar research on elements near palladium such as molybdenum and ruthenium. As a result, Schobachler's team knows what to expect from the palladium element.

Giant red stars (AGB stars) produce heavy elements like molybdenum or palladium.These elements form star dust.

Develop a new model

However, laboratory measurements do not confirm these predictions.'The meteors have a lower palladium ratio than predicted,' says scientist Mattias Ek of the University of Bristol in the United Kingdom.

In relation to the aforementioned issues, researchers develop a new model that can interpret measurement results. They claim that stellar dust is composed primarily of matter formed from giant red stars.

These aging stars increase in size as the fuel in the star's core is depleted. Our sun will also become a giant red star 4 - 5 billion years from now.

In giant red stars, heavy elements like molybdenum or palladium form during the capture of slow neutrons.

'Palladium is a more volatile element than molybdenum and ruthenium. So there is less palladium in the dust surrounding giant red stars, '' Mattias Ek said.

Researchers at ETH also offer an explanation for another mystery, related to stellar dust: On Earth there are more stellar dust from giant red stars than on Mars, on the asteroid Vesta or the Other asteroids.

'When the planets form, the temperature near the Sun is very high,' said Ms. Schobachler. High temperatures cause unstable dust particles to evaporate. Interstellar matter contains many types of dust that evaporates near the Sun; meanwhile, star dust from giant red stars is more resistant to heat and gradually accumulates in the inner regions of the fledgling Solar System.

It is likely that the dust in supernova explosions also evaporates faster.'This helps us explain, why the dust from giant red stars is more on Earth than other celestial bodies in the Solar System,' ' said Professor Schonbachler.

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