Answer to Universe Puzzle No. 13 Now Posted By Jean Tate - May 15, 2010 01:52 PM UTC | Cosmology I've now posted the answer in the original post . Our latest video — free on Patreon Vera Rubin Finally Delivers Its First Big Discovery The extended edition: ad-free, with extra content. Free to watch — no account needed. ▶ Watch it free Previous Article ← Rare Images of Shuttle Booster Return Next Article Astronomy Without A Telescope - Making Sense Of The Neutron Zoo →