A new paper by astronomers suggests that life on Earth might have been kickstarted by space dust containing microscopic organisms such as tardigrades (pictured), which can survive travel in space. Formerly, it was believed that such transfers could only be accomplished by asteroid or comet impacts.
Interestingly, it's thought such streams of dust are not only arriving here, but capable of being swept off Earth and migrating out into space.
Interplanetary dust is quite common throughout our solar system, and actually around 220,000 pounds of it land on Earth every day. Now that's dust bunnies on a cosmic scale!
More at Astronomy magazine.