Despite the few scattered clouds on Dec. 14, each tower recorded many detections. The next newsletter issue will provide a more detailed report.

The Source of the Geminid Meteors

We are fortunate to be witnessing the last major meteor shower of the year, which is being produced by 3200 Phaethon (FAY-ooh-thon), a unique asteroid classified as a rock comet since it exhibits characteristics of both asteroids and comets. In 1862, the Geminids were first observed and recognized as an annual phenomenon. However, the shower's source was not discovered until 1983, when Phaethon was discovered.

In an orbit that approaches the Sun closer than any other named asteroid, Phaethon is a small asteroid measuring only about 5 kilometers in diameter, which loops around the Sun every 1.4 years. It emits rocky dust instead of the ice-related vapors seen on comets when it approaches the Sun, which heats its surface to approximately 700 degrees Celsius. Dusty debris is roughly the size of sand grains or peas.

Throughout history, these bits of Phaethon have scattered throughout the asteroid's orbit to form a sparse, moving "river of rubble" that Earth passes through every December in the middle of the month. It is estimated that these particles travel 36 km per second when they come into contact with our planet. Air friction causes them to vaporize as soon as they dive into our planet's upper atmosphere, about 80 to 100 kilometers above the planet's surface.