COLUMBUS, Ohio (WCMH) — A recently discovered comet will make its closest approach to Earth by mid-December.
Comet Leonard (C/2021 A1), named after the astronomer Gregory Leonard who first observed it in January, is visible below the handle of the Big Dipper in the eastern sky to the left of the bright star Arcturus.
Around Dec. 5, the narrow window for seeing the comet was 90 minutes before sunrise, which will shift later each night through Dec. 10, when the viewing time will be a half-hour before sunrise. (See the charts in EarthSky.)
Don Stevens, director of Perkins Observatory at Ohio Wesleyan University, added the important caveat that after Dec. 10 the comet “will be too close to the sun to be safely viewed” in the early morning sky. The sun’s glare will make viewing hazardous when it sails past Earth very low on the horizon during its closest approach Dec. 12 at a considerable distance of more than 21 million miles.
The good news is that Comet Leonard will reappear in the evening sky around Dec. 14, low in the southwest and below Venus, about a half-hour after sunset. The comet will grow dimmer as it moves farther away and makes its closest approach to the sun on Jan. 3 (perihelion), before departing our solar system.
Stevens recommends using a miniature telescope or binoculars to catch the comet. “Through binoculars, the comet will look like a faint fuzzy star as the comet moves relative to the background stars,” he said.
“Long period comets have orbital periods of over 200 years up to millions of years,” so this will be our only chance to see Comet Leonard.
The Geminid meteor shower will peak late on the night of Dec. 13-14. The meteor shower happens at the same time each year in mid-December, when Earth’s orbit passes through leftover debris from an asteroid (3200 Phaethon) that has been called a “rock-comet” because of its composition, with a tail but not made of ice like a comet.
The asteroid has an orbit of 524 days (1.43 years). Particles from the 3200 Phaethon that collide with Earth’s upper atmosphere are moving at 37 miles per second, generating friction and burning up, leaving greenish streaks of light. The meteors are composed of iron, magnesium and sodium.
“This shower is called the Geminids because the radiant point (the constellation Gemini, the twins), the point in the sky the meteors appear to originate from, is in the constellation of Gemini, the twins. You do not need binoculars or a telescope to view the meteor showers. You just need clear dark skies,” said Stevens.
After the bright waxing gibbous moon sets after 2 a.m. (moonset in Columbus is 2:24 a.m.), we could see a few dozen meteors per hour for several hours. To view the Geminids, find a location with a relatively clear horizon and look over the entire sky. Allow a little time for your eyes to adjust to the dark sky, and then prop up a reclining lawn chair. Of course, a warm jacket and blanket are required this time of year.