Open Science is high on the European Union agenda as one of the prime instruments for a more transparent, effective and competitive research environment. Recently, key organizations, such as library and Universities associations, as well as Ministries of European countries have joined the stream of calls for a transition to a new scientific paradigm. LIBER, the leading network of European Research Libraries, is running its new strategy for the period 2018-2022 "Research Libraries Powering Sustainable Knowledge in the Digital Age". The strategy has a strong interest in Open Science that was recently expressed through publishing the Open Science Roadmap. The Roadmap describes the context that has been shaped, the challenges that research libraries face and the pillars of Open Science activities. Together with other documents and activities it aims to enable libraries to familiarize, embrace and facilitate Open Science. It also becomes clear that Open Science will be a key discourse topic between libraries, researchers and societies, and at the end of the dialogue all should be persuaded about a cultural change that will help the European research landscape to progress.