Ancient Stardust Trapped in Antarctic Ice Reveals Earth's Cosmic Journey

Scientists have discovered traces of stardust trapped in Antarctic ice, dating between 40,000 and 81,000 years old. The findings, published in Physical Review Letters, identify the presence of iron-60, a rare isotope formed exclusively during supernova explosions. Because this isotope has a relatively short half-life of 2.6 million years, its presence confirms an extraterrestrial origin rather than terrestrial formation. The research team, led by astrophysicist Dominik Koll from the Helmholtz Center Dresden-Rossendorf, analyzed 295 kilograms of ice samples collected under the European Antarctic Ice Core Project (EPICA). These ice cores serve as vertical time capsules, recording Earth's passage through the Local Interstellar Cloud. The data indicates that the Solar System has been moving through this region of gas, dust, and plasma for at least 80,000 years. Furthermore, the study reveals that the interstellar cloud was less dense in the past compared to recent decades, as evidenced by lower iron-60 concentrations in older ice layers. This discovery provides crucial insights into the evolving local interstellar environment and reconstructs Earth's historical journey through the cosmos.