This document outlines the Grand Research Challenges for Technology-Enhanced Learning (TEL) being prepared by a European group. It describes the STELLAR Network of Excellence, which received 5 million euros from the EU and 6.4 million euros total. It encourages readers to get involved. It then lists 10 top challenges rated by 40 experts, including using data to improve teaching/learning, new devices for young children's scientific expression, fostering engagement, e-assessment, and more. It provides more details on some challenges and notes more are challenging. It promotes joining its efforts to smooth the path to TEL2020.