Great Winter Constellations Hanging in There!
March is the month of the vernal equinox, the astronomical beginning of spring. This year the equinox falls on March 20th or 21st, depending on where you are on the Earth. Days and nights are both about twelve hours each. From then until late June in the northern hemisphere, the days will grow longer as the sun reaches higher and higher in the sky. Sadly, at the same time, stargazers will see continued erosion of their time under the heavens, so make the most of these longer March nights!
The marvelous constellations of winter will put on a great show all month, dominating the south-southwest heavens in the early evenings. Even so, they’re starting their long goodbye. Majestic Orion is the ringmaster of the winter heavens, surrounded by his posse of bright constellations. They include Taurus the Bull, Auriga the Charioteer, Orion’s hunting dogs Canis Major and Minor, and Gemini the Twins. On a slow retreat from the Earth, the planet Mars migrates from Taurus to Gemini. You can still see the red-orange hue of Mars with your naked eye, but honestly, being that it’s a small planet now well over 100 million miles away, it’s not much of a telescope target.
The three bright stars in a row that form Orion’s belt jump out at you. Below his belt are three fainter stars in a row that outline the hunter’s sword. The middle star is the famous Orion Nebula. It appears as a “fuzzy star” to the naked eye and is a superb telescope target, even if you have a small scope. You’re witnessing a giant cloud of excited hydrogen gas with stars forming gravitationally within it. Traveling there would require a journey of more than 1300 light-years, and just one light-year equals nearly six trillion miles! You can see a tight cluster of four stars within the Orion Nebula using a small telescope. They’re called the Trapezium stars because they’re arranged in a tight trapezoid pattern.
In the northern sky, the Big Dipper, the rear end and tail of the constellation Ursa Major, the Big Bear, stands on its handle. The fainter Little Dipper, or Ursa Minor, the Little Bear, hangs by its handle to the left of the Big Dipper. The bright star Polaris, also known as the North Star, shines at the end of the Little Dipper’s handle. Polaris is directly above the Earth’s terrestrial North Pole, so all of the stars in the northern hemisphere appear to circle the North Star every 24 hours in response to the Earth’s rotation.
In the early evening eastern sky, the first of the major spring constellations, Leo the Lion, is on the rise. Look for a distinct backward question mark of stars that outline the chest and head of the mighty beast. At the bottom of the question mark is Regulus, a moderately bright star that marks the heart of Leo. As March continues, Leo will be higher and higher in the sky at the start of the evening as the stars of Orion and his gang start lower and lower in the west. It appears as if the mighty lion is chasing Orion and his gang out of the night sky. This is due to the Earth’s orbit of the sun. The nighttime side of the Earth is gradually turning away from the direction of space where Orion and company are located and more toward the not-so-vibrant spring constellations. Enjoy the winter constellations while we still have them!
This month, the full moon is on March 7th. Leading up to that date, and for several nights afterward, too much moonlight in the evening sky will make it challenging for hardcore stargazing. The March full moon has several nicknames and is probably best known by the name given by early Native Americans who called it the Worm Moon. That’s because March is the time of year when the ground begins to soften, allowing earthworms to emerge. On March 21st, the very thin new crescent moon will be almost “touching” Jupiter in the very low western sky during evening twilight. On the 22nd and 23rd, a fatter crescent moon will be hanging by Venus higher early evening western sky. On March 27th and 28th, the nearly first quarter (half moon) will pass close to Mars in the high western evening sky.
Make the most of the wonderful night skies of March as the great constellations of winter gradually retreat from the heavens!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul, and is author of the book, “Stars, a Month by Month Tour of the Constellations” published by Adventure Publications. Available at bookstores and online at www.adventurepublications.net.
If you have any astronomical questions or want me to write about something you’re seeing in the night sky drop me a line at firstname.lastname@example.org