At http://phys.org/print335198820.html … hailstones in storms can for around biological material that is swept up and bounced around clouds. In the process they pick up an ice coating that may then rain down as hail stones.
Meanwhile, at www.spaceweather.com and http://phys.org/print334997812.html … the giant sun spot has returned and is now in view again, bigger than ever. It is the largest sun spot in over 20 years so a certain amount of hype is being poured over the phenomenon. That is understandable as the present solar cycle has been fairly quiet – and Sun watchers have had little excitement. It is in the process of rotating back to face the Earth.