Naval Observatory Tour

We were very lucky today to have a two-hour guided tour of the Naval Observatory, where Blake has his office. We went over to Terri's, and she drove us to the Observatory. Molly wasn't feeling well so she stayed home in bed.

Blake met us when we arrived and led us in. Our first impression was of being in a museum: the walls were lined with historic photographs and portraits.

Our tour leader, Bob, was very well versed in and enthusiastic about his subject. Our tour started in the James Melville Gilliss Library. Bob is standing by the Asaph Hall desk which regularly serves as the backdrop when Vice President Biden (who lives on the grounds of the Observatory) speaks to the media.

We learned a great deal about the history of the observatory, going back to Asaph Hall, who discovered the moons of Mars while working as an astronomer at the USNO, and Matthew Maury, its first superintendent and the visionary who guided it through the early formative years.

We saw one of the copper plates produced by Maury to show information related to navigation he had gathered by examining ships' logs. The information on the plates, including the lettering, had to be laboriously etched into the surface by hand with a pin.

We got to see the 26-inch refractor telescope which Asaph Hall used to discover the moons of Mars. It is still used by the Observatory's two astronomers to study double stars, making it the oldest instrument in the Department of Defense still in regular use for its original purpose.

We learned a lot about the missions of the USNO, including determining the positions and motions of the earth and other celestial objects, required for measuring time precisely. Time is measured by an ensemble of atomic clocks which now include ensemble of cesium beam and hydrogen maser atomic clocks. Rubidium fountain clocks will soon join the ensemble.

From the roof of the Observatory we could see the DC skyline, dominated by the Capitol Dome and the Washington Monument. Looking in a different direction, we got this great view of the National Cathedral.

One thing that impressed us was learning that the Navy used to have an official black widow spider farm. The silk spun by black widows is strong and thin, just the qualities needed for crosshairs for telescopes. The Navy now uses tungsten for that purpose.

We were impressed by the tour, which offered a broad combination of historical and scientific information and priceless opportunities to see some wonderful artifacts up close and personal. Thanks, Blake!

We stopped at Whole Foods on the way back to Terri's, where we had sandwiches for lunch. Then we sat down. The TV was on and both of us were soon nodding off.

For dinner Terri served Trader Joe's pizzas and broccolini and salad, all delicious. We watched CSI for a while and then went for our walk--with umbrellas at the ready, since it was showering and threatening to storm.