Beta decay data of nuclei far from stability are one of the most important nuclear physics inputs for the understanding of the element synthesis in the universe and determination of the age of the universe from cosmochronometers and by the latter have implications for cosmology. Results of new second‐generation microscopic calculations of &bgr;−half‐lives, will be presented. The impact on the above astrophysical questions will be discussed. New results for &bgr;&bgr;‐matrix elements for all potential &bgr;&bgr;‐emitters withA≥70 are given. It results that neutrinoless double beta decay remains the most powerful tool for investigating the electron neutrino mass. Perspectives of a second‐generation &bgr;&bgr;‐experiment using enriched76Ge (Heidelberg‐Moscow cooperation) are briefly presented.