In a circular plot of land in upper Northwest, the U.S. Naval Observatory has acted as America’s timekeeper for over 150 years. Most people associate the USNO with the Vice President, but Number One Observatory Circle – a house sitting on the grounds, separate from Navy operations – has only been the VP’s official residence since 1974. The real cultural and scientific draw of this institution is its role in using the Sun and stars…

A couple of readers have written us to ask why the Master Clock at 34th Street and Massachusetts Ave NW, at the entrance of the U.S. Naval Observatory, hasn’t been working for the last few months. We asked Geoff Chester at the USNO Public Affairs Office, who told us that the clock “had a little trouble dealing with the heat of a D.C. summer. So it’s back at the vendor getting fixed while we…