Esko Jorma Johannes Valtaoja (pronounced [ˈesko ˈʋɑltɑˌojɑ] ⓘ; born 20 June 1951) is a Finnish professional astronomer and writer.

Valtaoja retired in 2015 after holding a popular farewell lecture, that was also televised by Finnish national public broadcaster YLE.

[4] In 2002 his book Kotona maailmankaikkeudessa (At Home in the Cosmos, 2001) won the Finlandia Prize for the best non-fiction work.

Part of his popularity comes from his ability to present complex scientific theories and ideas in an understandable, entertaining manner to the general audience.

His latest book[needs update] is Ihmeitä: kävelyretkiä kaikkeuteen (Wonders: Saunters to the Universe), published in October 2007.