A team of scientists from the United States and Switzerland have discovered the oldest material on Earth, which is about 7.5 billion years old.

It hit the Earth from space with the meteorite Murchison, which crashed in Australia in 1969. Researchers took meteorite particles and turned them into powder. This paste was dissolved in acid to leave only star dust.

“It’s like burning hay to find a needle in it,” said Chicago Museum Curator and University of Chicago Assistant Professor Philip Heck.

To determine the age of this dust, scientists have determined how much it has been affected by cosmic rays. They are high energy particles that travel through our galaxy and penetrate into solid matter.

Therefore, scientists have been able to detect mostly particles that are 4.6-4.9 billion years old. For comparison, the Sun is 4.6 billion years old, and the Earth 4.5. At the same time there is dust in the meteorite, which is about 7.5 billion years old. Scientists also say that it probably has even older particles.