Microsoft Corp. co-founder Paul Allen announced a gift of $13.5 million to begin construction of an unprecedented new radio astronomy telescope in Northern California primarily dedicated to SETI, the Search for Extraterrestrial Intelligence. The gift is in addition to his earlier donation of $11.5 million.

The Allen Telescope Array will be a state-of-the-art network of 350 small radio-frequency dishes spread across about 2.5 acres of land. It will allow for exploring up to a million stars over the next decade, said Jill Tarter, director of research at the SETI Institute.