New research suggests that the solar system may have passed through a dense interstellar cloud about two million years ago, potentially plunging Earth into a “deep freeze” that caused multiple Ice Ages. These Ice Ages intermittently affected the planet until approximately 12,000 years ago.The solar system, which includes the Sun and its eight planets as well as several dwarf planets like Pluto, is enveloped in a “giant bubble” known as the heliosphere, according to NASA. This heliosphere is created by solar winds, a continuous stream of charged particles emitted by the Sun that travel up to three times the distance to Pluto.

The heliosphere acts as a protective shield, guarding the solar system from galactic cosmic rays that can alter our genetic makeup. The new study hypothesizes that the solar system’s journey through a dense cloud could have disrupted this protective barrier, allowing more cosmic rays to penetrate the Earth’s atmosphere and potentially trigger climatic changes leading to Ice Ages.

This research offers a fresh perspective on the factors contributing to Earth’s climatic history and underscores the complex interactions between our planet and the broader cosmic environment.