Musings on $\pi$ Day

1. The Ubiquity of $\pi$      or, Life, the Universe, and Everything: A Simple Statement of Fact $\pi$ is everywhere you look. It is even the case that there is $\pi$ in the sky. We need $\pi$ in order to live … Continue reading

Moonlit Snowscape

The Moon illuminates a snowy scene (my back yard) in the pre-dawn darkness. This is an 80 second exposure at 35mm f/3.2 and ISO 125. The yellow-gold color on the background trees is from low-pressure sodium streetlights on the next … Continue reading

Twilight Dome Fun

Here are a few images from goofing around yesterday evening with the NOFS 61-inch telescope, dome, and twilight. Images were taken with a Canon G3 X at ISO 125 on 2019-02-07 MST. Click on an image to enlarge; right-click to … Continue reading

When I am at my desk, preparing for tonight’s observing. And it is evening.

Notes to self, part 437. When I am at my desk, preparing for tonight’s observing. And it is evening. If an email arrives from the satellite tracking app, you could open it. Be aware that this alert is for tonight. … Continue reading

The ISS Passes over Flagstaff

Moved to here. … Continue reading

Preparations

The evening looks promising. Transparent air, crystalline blue—emblematic of Flagstaff even in summer—has soothed my soul since childhood. “I can see for miles and miles…” spins in my head, unbidden, as I walk a short patch of worn asphalt, dull gray and pitted from winter’s … Continue reading

Prolegomenon

You recognize as a youngster that science, and music, and literature and writing—creative wonders—draw you along comfortable invisible force lines.† But not opera. Overbearing, embarrassing falsetto vibrato is just wrong. As your joints grow creaky and more of your pate warms to the Sun, you … Continue reading

Flagstaff Skywheel 2015-11-07

Dark skies are a treasure, a part of our culture, a part of who we are as humans that we must preserve. Due to some enlightened and forward thinking in the late 1980s, the outdoor lighting code implemented in Flagstaff … Continue reading

Zodiacal Light West of Flagstaff, Feb. 2015

The zodiacal light at 7:51 pm (MST) on February 10, 2015, as seen from the west parking lot of the U.S. Naval Observatory near Flagstaff. If you’re wondering where the Observatory is, it’s about five miles west of downtown (Google maps link). … Continue reading

DDA 2015 – Constraints on Titan’s rotation from Cassini mission radar data

This is one of a series of notes taken during the 2015 meeting of the AAS Division on Dynamical Astronomy, 3-7 May, at CalTech. An index to this series (all the papers presented at the meeting) is here. Bruce Bills (JPL) … Continue reading

DDA 2015 – Recent Formation of Saturnian Moons: Constraints from Their Cratering Records

This is one of a series of notes taken during the 2015 meeting of the AAS Division on Dynamical Astronomy, 3-7 May, at CalTech. An index to this series (all the papers presented at the meeting) is here. Session: Moon Formation and … Continue reading

DDA 2015 – On the Spin-axis Dynamics of the Earth

This is one of a series of notes taken during the 2015 meeting of the AAS Division on Dynamical Astronomy, 3-7 May, at CalTech. An index to this series (all the papers presented at the meeting) is here. Gongjie Li (Harvard) … Continue reading

DDA 2015 – Recent dynamical evolution of Mimas and Enceladus

This is one of a series of notes taken during the 2015 meeting of the AAS Division on Dynamical Astronomy, 3-7 May, at CalTech. An index to this series (all the papers presented at the meeting) is here. Session: Moon Formation and … Continue reading

DDA 2015 – On the in situ formation of Pluto’s small satellites

This is one of a series of notes taken during the 2015 meeting of the AAS Division on Dynamical Astronomy, 3-7 May, at CalTech. An index to this series (all the papers presented at the meeting) is here. Man Yin Woo … Continue reading

DDA 2015 – Rotational and interior models for Enceladus II

This is one of a series of notes taken during the 2015 meeting of the AAS Division on Dynamical Astronomy, 3-7 May, at CalTech. An index to this series (all the papers presented at the meeting) is here. Radwan Tajeddine (Cornell) … Continue reading