The effect this will have on our planet - if any - is unknown. But some researchers have speculated that sustained periods of cosmic dust bombardment might be related to ice ages and even mass extinctions.

During the last decade, the magnetic field of the Sun acted like a shield, deflecting the electrically charged galactic dust away from the Solar System. However, the Sun's regular cycle of activity peaked in 2001.

As expected, its magnetic field then flipped over, so that south became north and vice-versa. In this configuration, rather than deflecting the galactic dust, the magnetic field should actually channel the dust inwards.

Mass extinctions have occurred in Earth's past. That much is clear, from the fossil record. But what cause them is less certain. A widespread die-off 65 million years ago, which wiped out the dinosaurs and many other species, is thought by most scientists to have been caused by an asteroid impact.

Other extinctions have been attributed to impacts, climate change, cosmic rays, exploding stars, increased volcanic activity and even global warming. Multiple events may have conspired to make life difficult in any one of the five known worst mass extinctions.

The idea that we pass through clouds of galactic debris is not new. In fact, a 2003 study found that we're traveling through a mild one right now.