January’s Astronomy Highlights

Jan. 3-4

Quadrantid meteors: all night

Jan. 4/5

Moon near Venus: 5-6 a.m.

Jan. 18/19

Moon near Mars: after 5:30 p.m.

Jan. 22

Full Moon in Gemini: all night

Jan. 24

Moon near Saturn after 7 p.m.

Jan. 31

Venus near Jupiter 5:30-6:30 a.m.

Is there any sight more beautiful than sparkling nighttime stars seen over a snowy landscape in Maine?

January is the month when the stars are the best for several reasons, First, the sky is more transparent because the haze and humidity of summer are (long!) gone. Second, the frigid air creates convection currents that make the stars twinkle more.

And, third, you are looking toward the Orion spur of the nearest spiral arm of the Milky Way galaxy. Astronomers have observed that spiral arms are marked by many massive bluish-white stars that are very luminous. Winter stargazing is one of the simple pleasures of living in Maine, at least, if you are dressed right. If you are not, you are inviting frost-bite.

Constellation of the Month: Gemini

Ancient Greek and Roman mariners saw the celestial twins Castor and Pollux as their protectors. This famous pair of sailors protected Jason and his Argonauts on their voyage in search of the golden fleece. Legend has it that Pollux was immortal while his brother Castor was not. When Castor died, the gods placed the devoted twins close together for all time as stars in the sky. Castor and Pollux mark one end of the rectangle that outlines the constellation of Gemini.

These two stars are among the 30 brightest stars in the sky. Castor, which appears to the eye as a single star, is actually a fascinating “triple-double” star with six suns of different colors and sizes mutually orbiting each other. Science fiction writer Isaac Asimov used Castor as a basis for his story “Nightfall” about a planet where darkness came only once every 2,000 years when an eclipse occurred. Gemini can be located by drawing an arrow diagonally from Betelgeuse through Rigel in Orion.

Events for January

January begins with one of the year’s best meteor showers. This year’s Quadrantid shower peaks on the night of Jan. 3/4. If the skies are clear, any observer from a dark site should see 40-70 streaking meteors per hour from the general direction of the Big Dipper. Venus is the morning “star” all month and makes a nice grouping with the crescent Moon on the mornings of Jan. 4 and 5.

Even with so many bright stars in the evening sky, reddish Mars is unmistakably brilliant in Taurus. Mars is close to the Earth now and is as bright as it will be for the next two years. On Jan. 24 the Moon is near Saturn in Leo after 8 p.m. The month wraps up with a spectacular conjunction between Venus and Jupiter on Jan. 31 between 5:30 and 6:30 a.m. Bundle up and take a look.

Jay Sarton lives in Gray and works at USM’s Southworth Planetarium.