NB: This is not a duplicate of this question, because A) it only asks to wipe out humans, not any other life-form, and B) it insists that one person must survive. The survival of anything is not possible in my scenario, and all of the answers are not applicable to wiping out other animals, plants, fungi and microbes.
This may be a duplicate, but I'm yet to come across a similar question.
Basically, my question is simple; What natural events could wipe out all organisms on Earth, including prokaryotes, in only 15 years, but leave the Earth habitable to microbes at the end of those 15 years?
The 15 year figure can be stretched to up to 35 if it's necessary, and yes, I know it's a really short amount of time. One other requirement is that the disaster must not harm orbital space stations.
That's more or less it, comment if you need any more information.