Old Space Junk From the 1960s Just Revealed a Hidden Effect of the Sun on Earth’s Orbit
The Daily Galaxy • • science
Key Points:
- A study published in Frontiers in Astronomy and Space Sciences found that space debris in low Earth orbit loses altitude more rapidly during periods of high solar activity due to increased atmospheric drag from the expanded thermosphere.
- Researchers tracked 17 debris objects over 36 years and identified a "transition boundary" where orbital decay significantly accelerates once solar activity exceeds about two-thirds of its maximum intensity.
- The Sun's approximately 11-year cycle affects thermospheric density, with heightened ultraviolet and charged particle emissions during solar maximum causing stronger drag on orbiting objects.
- These findings suggest that satellites in low Earth orbit may require more frequent orbit corrections and additional fuel during periods of strong solar activity to maintain stable altitudes.
- The study highlights the continued scientific value of long-forgotten debris from the 1960s as indicators for understanding solar activity's impact on Earth's upper atmosphere and orbital dynamics.