NASA Study Suggests Giant Space Clouds Iced Earth

Eons ago, giant clouds in space may have led to global extinctions, according to two recent technical papers supported by NASA's Astrobiology Institute. One paper outlines a rare scenario in which Earth iced over during snowball glaciations, after the solar system passed through dense space clouds. In a more likely scenario, less dense giant molecular clouds may have enabled charged particles to enter Earth's atmosphere, leading to destruction of much of the planet's protective ozone layer. This resulted in global extinctions, according to the second paper. Both recently appeared in the Geophysical Research Letters.

"Computer models show dramatic climate change can be caused by interstellar dust accumulating in Earth's atmosphere during the solar system's immersion into a dense space cloud," said Alex Pavlov, principal author of the two papers. He is a scientist at the University of Colorado, Boulder. The resulting dust layer hovering over the Earth would absorb and scatter solar radiation, yet allow heat to escape from the planet into space, causing runaway ice buildup and snowball glaciations.

Explains the sudden freezing where animals and plants were frozen alive.

Moderately dense space clouds are huge, and the solar system could take as long as 500,000 years to cross one of them. Once in such a cloud, the Earth would be expected to undergo at least one magnetic reversal. During a reversal, electrically charged cosmic rays can enter Earth's atmosphere instead of being deflected by the planet's magnetic field.

The solar system is passing through an interstellar cloud that physics says should not exist. "This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all." It's about 30 light years wide and contains a wispy mixture of hydrogen and helium atoms at a temperature of 6000 C.


Personal note: Time to purchase propane heaters.