Archive · 26 Aug 2026
NASA Study Links Sun’s Galactic Journey to Earth’s Ancient Climate
The Sun travels through different parts of space as it moves through the Milky Way.
Around the solar system is a protective bubble called the heliosphere.
Scientists used computer simulations to study how this bubble changed over time.
They found that the Sun may have passed through very cold, dense clouds at least three times in the last 14 million years.
These clouds could have squeezed the heliosphere to a much smaller size.
That may have allowed more space material and radiation to reach Earth.
The researchers think this could have changed moisture in the upper atmosphere and affected global weather.
They say these changes may have helped cause some ancient ice ages.
Dust found in ocean sediments, lunar samples, and Antarctic ice provides supporting physical evidence.
NASA-funded simulations suggest the Sun passed through extremely dense, cold interstellar clouds at least three times over 14 million years.
Pressure from those clouds may have compressed the heliosphere, the solar system’s protective bubble of charged solar winds.
The smaller heliosphere may have exposed Earth more directly to interstellar hydrogen and cosmic rays.
Researchers say the exposure could have increased upper-atmosphere moisture and altered global weather patterns, potentially contributing to ice ages.
Traces of interstellar dust found in ocean sediments, lunar samples, and Antarctic ice support the study’s conclusions.
- Who
- Scientists at NASA’s SHIELD centre conducted the research.
- What
- Computer simulations suggest that the Sun’s passage through dense interstellar clouds compressed the heliosphere and influenced Earth’s ancient climate.
- When
- The study examined the last 14 million years, during which the Sun may have passed through such clouds at least three times.
- Where
- The events occurred as the solar system traveled through interstellar space within the Milky Way galaxy.
- Why
- Dense clouds may have compressed the heliosphere, exposing Earth to more interstellar hydrogen and cosmic rays, which could have altered atmospheric moisture and global weather.
- Research sponsor
- NASA-funded
- Research group
- NASA’s SHIELD centre
- Period studied
- The last 14 million years
- Number of cloud passages
- At least three
- Protective structure
- The heliosphere, a bubble of charged solar winds
- Possible climate effects
- Increased upper-atmosphere moisture, altered weather patterns, and possible contributions to ice ages
- Supporting evidence
- Interstellar dust traces in deep-sea sediments, lunar core samples, and ancient Antarctic ice