Grab your winter coat and mittens, pour some coffee, step outside and look up: The Geminid meteor shower — arguably the most robust shooting stars of 2017 — peaks the night of Dec. 13-14.

The International Meteor Organization (imo.net) predicts that the Geminids will put on a good show starting about 10 p.m. Dec. 13 and continuing through the night.

The waning crescent moon will be in a last-quarter phase, so it won’t bathe the meteors in light. (The moon will rise at 3:43 a.m. Dec. 14, according to the U.S. Naval Observatory.)

Both the IMO and the Royal Astronomical Society of Canada forecast that the shower will peak at about 120 meteors an hour, provided there are dark, clear skies. The Geminids can be bright and have intense color, according to the IMO. So turn off porch lights, get away from streetlights and gaze into the cold sky.

Generally speaking, meteor showers are born from the dusty tails of comets. When comets approach the sun, they warm up and form a tail, spewing vapor and dirt. When Earth rounds the sun on its annual 365-day journey, our blue planet’s atmosphere inevitably strikes dirt from these leftover comet trails. The dust burns in our atmosphere, lights up and shoots across our heavens.

But the Geminids happen thanks to an asteroid: (3200) Phaethon (pronounced FAY-ah-thon), a rocky entity about three miles in diameter that sails close to the sun, heats up and sheds shards. When Earth runs into these rocky chips, they burn up.

In addition to tonight’s full moon (Dec. 3), the year’s largest, according to the Royal Astronomical Society, the planets Jupiter and Mars start playing a cosmic game of tag now and into January. Before sunrise, find the planetary pair in the southeastern sky. The big, gassy Jupiter is -1.7 magnitude (bright) far below the dim, reddish Mars (1.7 magnitude, hard to see in light-polluted urban and suburban conditions).

As the month progresses, Mars brightens and the two planets appear to scoot close together at the end of December for a conjunction early in the new year.

Venus, Saturn and Mercury are taking a holiday vacation — hiding in the sun’s glare, probably sipping cosmic mai tais. The fleet Mercury (zero magnitude, bright) returns to the morning heavens in late December in the southeast, popping up above to the horizon. Before sunrise, look in the direction of the bright Jupiter, then look lower toward the horizon and then to the left to find Mercury.

Our darkest days may soon be behind us. The upcoming solstice starts the winter season here in the Northern Hemisphere on Dec. 21 at 11:28 a.m. Eastern time, according to the Naval Observatory. Dec. 20-22, the Washington area gets nine hours and 26 minutes of daylight — the least amount all year. Starting Dec. 23, we’ll enjoy a smidgen more daylight (nine hours and 27 minutes), and it will increase until June.

Down-to-Earth Events

●Dec. 4 — Preview the late autumn and winter sky at “Stars Tonight” at the David M. Brown Planetarium, 1426 N. Quincy St., Arlington, adjacent to Washington-Lee High School. 7:30 p.m. $3. friendsoftheplanetarium.org.

●Dec. 5 — Appreciate undergraduate astronomical research at the University of Maryland’s Observatory in College Park. Afterward, behold the night sky through telescopes, weather permitting. 8 p.m. astro.umd.edu/openhouse.

●Dec. 9 — “Black Holes at All Scales: An X-ray View,” a talk by physicist Mario Gliozzi of George Mason University, at the regular meeting of the National Capital Astronomers, held at the University of Maryland Observatory in College Park. 7:30 p.m. capitalastronomers.org.

●Dec. 10 — Find out about telescopes and binoculars at the Northern Virginia Astronomy Club’s show-and-tell and swap meet, 163 Research Hall, George Mason University, in Fairfax.
7 p.m. novac.com.

●Dec. 20 — “TESS: The Transiting Exoplanet Survey Satellite,” a talk by astronomy professor Drake Deming, will explain NASA’s exoplanet-hunting mission, planned for a launch in the spring. Exoplanets are planets in other solar systems.

The talk will be held at the University of Maryland’s Observatory in College Park. Scope the dark heavens through telescopes afterward, weather permitting. 8 p.m. astro.umd.edu/openhouse.

Blaine Friedlander can be reached at SkyWatchPost@gmail.com.