Path of the solar system through the Local Interstellar Cloud. The cloud’s profile is preserved as an interstellar fingerprint in Antarctic ice. Credit: B. Schröder/HZDR/ NASA/Goddard/Adler/U.Chicago/Wesleyan Scientists have uncovered new evidence that Earth is traveling through a cloud of ancient stellar debris left behind by a long ago exploding star. By studying Antarctic ice that formed tens of thousands of years ago, researchers detected traces of iron-60, a rare radioactive form of iron