when stars explode, earth gets cold
Many folks agree that the planet suffered a small number of drastic cooling events (snowball earth); at least one between 2.2-2.4 billion years
ago and another 770 to 550 million years ago, but their triggers are a matter
of debate. Katoaka et al. (2013) suggest that the events could be driven by
encounters between Earth and cosmic dust and rays originating from stellar explosions (nebulae). They use the ages of stars, and star
clusters, to deduce a causal effect between the death (and subsequent growth) of
nearby stars in the Milky Way galaxy and periods snowball Earth. They also suggest that some of the major mass
extinctions in the Phanerozoic could also be related to encounters with remnants
from supernovae.
Image from Katoaka et al., showing interaction of stellar particles
with two of the Earth’s protective shields (geomagnetic field, and ozone
layer). The heliosphere provides further protection.
Reference, Kataoka, R., Ebisuzaki, T., Miyahara, H.,
Maruyama, S., 2013, Snowball Earth events driven by starbursts of the Milky Way
Galaxy, New Astronomy, 21, 50-62.
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