Our sun has been more active lately as it enters a new phase in its 11-year cycle, which is one reason we've seen a bunch of enormous coronal mass ejections and solar explosions in the past few months. But it's actually a pretty weak solar maximum, as solar maximums go, so heliophysicists believe the sun is entering a prolonged hibernation unseen since the 17th century. This has some major implications for climate changes - on Earth and in the heavens, according to one new study.
A chilled-out sun would spew fewer particles into space, meaning the sun's protective moat around the solar system would be less powerful. Galactic cosmic rays could have an easier time getting through, which means they could pose an increased radiation risk to astronauts and air passengers. Under these space weather conditions, a crewed asteroid or Mars mission would be far more dangerous, if not impossible.
To test whether this is really happening, you would need to study galactic cosmic ray penetration over the centuries. Michael Lockwood and colleagues at the University of Reading in the United Kingdom looked at a 9,300-year record from ice core samples from the north and south poles.
