2 million-year-old interstellar cloud encounter may have caused Earth's ice ages, according to astronomers.

Astronomers from Boston University, Harvard University, and Johns Hopkins suggest that Earth might have experienced ice ages due to an encounter with an interstellar cloud around 2 million years ago. The researchers propose that the dense cloud altered the Sun's solar wind, leading to changes in Earth's climate. This theory has been published in the journal Nature Astronomy and suggests that Earth's climate history may be influenced by the sun's location in the galaxy.