Earth and other planets in our solar system have existed longer than previously thought, according to a new study of asteroid debris in a distant star system.
Published in Nature Astronomy on November 14Researchobserved the oldest stars in the universe and suggests that stars and planets grew together. It was previously thought that planets would not form until the star reached full size.
The sun formed from a cloud of gas 4.6 billion years ago, and the planets formed around it.
“We know pretty well how the planets formed, but one question that remains is ‘when?’ Was it while the parent star was still growing? , or millions of years later?” says Dr Amy Bonser of Cambridge University’s Institute for Astronomy.
The radio telescope antennas of the Atacama Large Millimeter and Submillimeter Interferometer (ALMA) project. Located on the Chajnantor Plateau in San Pedro de Atacama, Chile, regarding 1,500 kilometers north of Santiago (Getty Images)
Using the Atacama Large Millimeter-Submillimeter Interferometer in Chile, the researchers probed the atmosphere of a white dwarf (the remnant of a dead Sun-like star) looking for planetesimals, the building blocks of planets. “Some white dwarfs surprised the lab because their tenuous atmospheres were like graveyards in the sky,” says Bonser.
The white dwarfs studied are unique because their atmospheres are contaminated with heavy elements such as magnesium, iron and calcium. According to the authors, these elements must have come from asteroids born during planet formation that later collided with white dwarfs and melted in their atmospheres.
According to the paper, the process by which lighter elements float to the surface and iron sinks into the core is the reason why the Earth has an iron-rich core.
It is generally believed that planet formation began in rings of hydrogen, helium, and ice and dust particles orbiting young stars. Dust particles combine to form planetesimals, which over time grow into asteroids or planets.
This study suggests that planetesimals formed almost immediately. “If these asteroids were melted into something that existed for only a short time at the beginning of the planetary system, the process of planet formation must start very quickly,” Bonser said. Say. “Our work complements the growing consensus in the field that planet formation began early and that the first bodies formed at the same time as stars.”
Wishing for clear skies and big eyes.