Cosmic Dust May Affect Earth’s Climate

Big climate changes in the last million years might have come from something very small: dust from outer space.

Earth alternates between ice ages and warm periods in a pattern that includes several cycles, including a mysterious one that lasts 100,000 years. Scientists recently suggested this cycle might be due to changes in the influx of cosmic dust.

The idea is that Earth bobs above and below the imaginary plane that runs through the sun and Jupiter, completing a cycle every 100,000 years. So maybe it encounters regularly varying amounts of dust during each cycle that produce the climate trend, scientists suggested.

Now there’s some evidence, from ancient cosmic dust recovered in ocean-floor drilling near the Azores islands west of Portugal. The abundance of the dust rises and falls with an intriguing 100,000-year cycle during the period analyzed, 253,000 years to 458,000 years ago. Periods of more dust correlate with warm climates.