Gemind Meteors, Mars Opposition, Winter Solstice: What To Know In PA

PENNSYLVANIA — The most anticipated meteor shower the heavens have to offer — the colorful, showy Geminids — highlights December skywatching opportunities in Pennsylvania.

At their Dec. 13-14 peak, the Geminid meteor shower produces up to 120 multicolored meteors an hour late into the evenings. The nearly monthlong shower is currently active, running through Dec. 24.

The best views are always under dark skies away from streetlights and other artificial light, and it’s especially important for this beauty of a meteor shower. A waning gibbous moon rises just before 10 p.m. in Pennsylvania, and with 72 percent illumination, may wash out some of the meteors. But the Geminids are bright and prolific enough that they’re still expected to offer a good show.

Keystone State skywatchers don’t have to wait until the Geminids to see color in the sky. The reddish planet Mars, the second-smallest in our solar system, comes within 50 million miles of Earth on Thursday, making its closest approach to our planet as it orbits the sun.

Whether you’ll be able to gaze at the Red Planet during its close brush with Earth depends on weather conditions in Pennsylvania. Mars will be 4.5 light-minutes from Earth at about 1 a.m. Thursday. The Philadelphia area has a 76 percent chance of overnight cloud cover during that time, according to AccuWeather.

Mars and the sun are in opposition a week later, on Dec. 8, which will make the planet look more red.

All planets orbit the sun, but the Red Planet is pokey compared with Earth, taking about twice the amount of time in its trip around the sun as our planet. Because of that, Mars and Earth are sometimes very far apart in their orbits, and Mars appears as a very bright star. But when they catch up, as they are this year, Mars shines with an apparent magnitude of about -1.9 magnitude through early December.

“During opposition, Mars and the sun are on directly opposite sides of Earth,” NASA explains. “From our perspective on our spinning world, Mars rises in the east just as the sun sets in the west. Then, after staying up in the sky the entire night, Mars sets in the west just as the sun rises in the east. Since Mars and the sun appear on opposite sides of the sky, we say that Mars is in ‘opposition.’ ”

Mars begins to lose some of its brilliance, dimming to around a -1.4 apparent magnitude by the end of the month.

Mars in opposition coincides with the Dec. 7 full moon, the full cold moon, which reaches peak illumination around 11:09 p.m. that evening.

Native Americans have ascribed names to the moons to track the season. Cold moon was bestowed by the Mohawk people because temperatures are typically frigid at this time of year, but as The Old Farmer’s Almanac explains, the December full moon has been given other names by indigenous peoples.

Some of them include the drift clearing moon, frost exploding trees moon and hoar frost moon (Cree); moon of the popping trees (Oglala), snow moon (Haida, Cherokee); and winter maker moon (Western Abenaki).

Fall officially yields to the cold, snowy season with the Dec. 21 winter solstice at 4:48 p.m. That’s the exact moment the Earth’s South Pole reaches its maximum tilt away from the sun. This is known as the “shortest day” and “longest night” of the year.

Finally, don’t forget the Ursid meteor shower. The Ursids aren’t nearly as showy as the Geminds, with only five or 10 shooting stars an hour, but the moon will only be about 3 percent full during the Dec. 21-22 peak.

This shower begins Dec. 13 during the Geminids peak and runs through Dec. 24.

The Quadrantid meteor shower runs Dec. 26-Jan. 16, peaking Jan. 4 during a small, six-hour window with about 25 shooting stars an hour. The unpredictable Quadrantids have the potential to be the strongest meteor shower of the year, but poor weather conditions at this time often deter all but the most faithful of skywatchers. The Quadrantids are known for producing bright fireballs, according to the American meteor society.