The Geminid meteor shower peaks Wednesday evening

The Geminid meteor shower produces one of the best shows of the year and conditions are close to ideal for the peak on Wednesday evening, December 13, 2023.

Clouds and moonlight, the things that usually spoil a meteor shower, wont be a problem this year. Mostly clear skies are forecasted for Wednesday evening with clearing continued through peak viewing time at 2 a.m. through sunrise.

Past meteor showers have been hidden by moonlight, but not this year. The Moon reached new phase earlier this week which means it will set just after sunset.

Meteor showers are created as Earth passes through trails of dust and tiny bits of rock ejected by passing asteroids and comets, estimated at about a billion tons for the Geminids. Much of that debris is the size of a grain of sand but the most brilliant meteors come from pea sized rocks entering the upper atmosphere at thousands of miles per hour.  Earth itself is moving around the sun at 67,000 mph.

Comets and asteroids are similar, made up of varying levels of ice and rock. Both are leftovers from the formation of the solar system 4.5 billion years ago.  Comets have more ice than rock and asteroids more rock that ice. The Geminids are coming from asteroid 3200 Phaethon which scientist think is more asteroid than comet but still uniquely somewhere in between.

Asteroid Phaethon even has a tail, made not of dust like it's cometary cousins, but vaporized sodium discovered by researchers at the California Institute of Technology in a study published in the April 2023 Planetary Science Journal. Data from NASA's Solar and Heliospheric Observatory (SOHO) and Solar Terrestrial Relations Observatory (STEREO) missions not only showed Phaethon's tail was made of sodium not dust, but gave clues about why the Geminid meteor shower produces so many meteors, more than expected from asteroid (or comet) its size.

The CalTech team, led by PhD student Qicheng Zhang, theorize that Phaethon may have broken apart long ago under the stress created by its rotation, leading it to eject tremendous amounts of debris which have lingered along its path over thousands of years.

Astronomers hope to learn more about this odd asteroid in a flyby by the Japanese Space Agency's DESTINY+ mission scheduled for launch next year.

To see the most meteors

• The longer you look, the more you'll see. There may be quiet periods followed by two or three meteors per minute. Be patient and....
• Bundle up. Temperatures will be in the upper 30s
• Give your eyes at least 15 minutes to adjust. You will be surprised how many more stars will be visible. Also leave your phone inside. Each time you look at it, the timer on regaining your night vision starts over
• Look to the darkest part of the sky. That might not be to the east toward the constellation Gemini. That's okay, meteors can appear anywhere in the sky.
• Meteors should be visible by 10 p.m. earlier than that, many meteors will be hidden below the horizon as Gemini rises.
• Best time to watch for meteors in the hours around 2 a.m. when Gemini is at its highest in the sky.

About those claims of "hundreds" of meteors per hour

You are very unlikely to see 100 or more meteors per hour you have seen elsewhere. This number likely comes from the Zenith Hourly Rate (ZHR) which assigned to help measure scientists meteor showers from year to year. It is not intended as a predictor for meteor activity.

ZHR is a handicapping system to help compare observations from around the world.  it mathematically removing all the things that hide meteors from view like clouds, light pollution, and the horizon. You could expect to see 120 meteors per hour only if skies were completely clear (we'll be close, but not quite) with no light pollution (only possible from very dark locations like the desert) and with the constellation Gemini directly overhead (it's wont be).

Hourly rates of 50-60 are anticiapted for darker, rural skies and a few dozen from the suburbs.