In this issue of Sky’s Up, SETI senior astronomer Seth Shostak answers 10 Questions about the search for extraterrestrial life, and the Pedaling Astronomer talks about his unique coast-to-coast outreach effort. Additional features include a piece on the Messier Marathon observing challenge, a STEM activity on lunar motion, a detailed tour of some of the Moon’s standout features, columns, an astrophotography gallery, event calendars, star maps and more. 更多
