Category Archives: Astronomy

Measuring the Solar System

Thousands of years ago, ancient astronomers like Aristarchus and Eratosthenes combined careful observations with simple mathematics to measure the solar system, especially the diameters D of Earth, Luna (Earth’s moon), Sol (Earth’s star, the sun), and the radii r of their … Continue reading

Posted in Astronomy | Leave a comment

The Ringed Planets

When I was a kid, Saturn was the ringed planet. But today, we know that all of the outer planets have rings. The James Webb Space Telescope has now imaged each of them in infrared revealing their distinctive structures, including … Continue reading

Posted in Astronomy | Leave a comment

Compton Generator

Long before he won the Nobel Prize in Physics, and while still a Wooster undergraduate, Arthur Compton realized a third way to demonstrate Earth’s spin (after pendulums and gyroscopes). Compton reported his results in a manuscript submitted to the journal … Continue reading

Posted in Astronomy, Physics, Wooster | Leave a comment


Photograph the sky at the same time each day for a year and Sun will appear to execute a figure-8 path called an analemma, which is often inscribed on Earth globes and can be used as an almanac, as by … Continue reading

Posted in Astronomy | Leave a comment

Distant Retrograde Orbit

The Artemis 1 mission’s Orion spacecraft has successfully entered and exited a distant retrograde orbit about Moon. DRO is a stable and easily accessible orbit requiring a low velocity change . In DRO, Earth‘s non-negligible gravity contributes to a 3-body problem that … Continue reading

Posted in Astronomy, Exploration, Physics | Leave a comment

For the dinosaurs!

The dinosaurs didn’t have a space program, but we do. I just watched live the first kinetic-impact asteroid-redirection test as NASA’s Double Asteroid Redirection Test spacecraft collided with the asteroid-moon Dimorphos of the asteroid Didymos. Below is the last image … Continue reading

Posted in Astronomy, Physics, Space Exploration | Leave a comment

Great Plains Solstice Twilight

Last month I drove across the United States, coast-to-coast back-and-and forth diagonally, 8000 miles through 18 states, as in the animation below. Amazing was driving through the Great Plains of the North American flatland with uninterrupted 360° horizons as the … Continue reading

Posted in Astronomy, Travel | Leave a comment

Signature Spikes

Nearly a quarter century in the making, I was tremendously excited and relieved last week by the release of the first images from the James Webb Space Telescope. I remember the trials, tribulations, and triumph of the Hubble Space Telescope and … Continue reading

Posted in Astronomy | Leave a comment

Alien Suns Reversing in Exoplanet Skies

Not only can suns stand still in the sky, from some exoplanets their motion can apparently reverse! Wooster physics-math double majors Xinchen (Ariel) Xie ’21 and Hwan (Michelle) Bae ’19 and I just published an article elucidating these apparent solar reversals. Michelle … Continue reading

Posted in Astronomy, Mathematics, Physics | Leave a comment

Black Hole Above the Fold

When grocery shopping, I normally just glance at the newspapers in the newsstand. However, this morning, I was excited to see “above the fold” of the Wall Street Journal a large reproduction of the first image of the supermassive black hole … Continue reading

Posted in Astronomy, Physics | Leave a comment