Russian opposition plan Moscow rally

People are protesting against the exclusion of opposition candidates from local elections in September. Last weekend’s protests led to over a thousand arrests, one of the biggest crackdowns in Russia in years.

Also in the programme: as Germany gets ready to mark 250 years since the birth of one of its most beloved scientists, Alexander von Humboldt, we'll find out why he's been almost forgotten by the rest of the world.

(Picture: Russian riot police detain a protestor during an opposition demonstration in Moscow on July 27. Credit: EPA)