Great Winter Constellations Swan Song
We have so many special celestial happenings this month but even without them March is so fantastic for stargazing! Itís not as cold as January and February overall but the same great winter constellations are still available ready to enjoy!
The Vernal Equinox, the astronomically beginning of spring, takes place on March 19th or 20th, depending where you are on the Earth. Days and nights are both about twelve hours each. From now until late June in the northern hemisphere days will grow longer as the sun reaches higher and higher in the sky.
Despite spring beginning, the marvelous constellations of winter will put on a great show all month, dominating the early evening south-southwest heavens. Even so, theyíre starting their long goodbye. Majestic Orion is the ringmaster of the winter constellations surrounded by his posse of other bright constellations. They include Taurus the Bull, Auriga, the Charioteer, Orionís hunting dogs Canis Major and Minor, and Gemini the Twins.
The three bright stars in a row that make up Orionís belt jump out at you. Below his belt are three fainter stars in a row that outline the hunterís sword. The middle star is the famous Orion nebula, appearing as a fuzzy star to the naked eye. Itís a superb telescope target, even if you have a small scope. Youíre witnessing an excited cloud of hydrogen gas with stars forming within it. To travel there would require a journey over 1500 light-years. Just one light-year equaling nearly six trillion miles! With a small to moderate telescope, itís possible four stars with the Orion nebula that were gravitationally born out of it. The called the Trapezium stars because theyíre arranged in a tight trapezoid pattern.
In the northern sky, the Big Dipper is standing up on its handle. The fainter Little Dipper is off to the left hanging by its handle. The brightest star, Polaris, otherwise known as the North Star, shines at the end of the Little Dipperís handle. Polaris shines directly above the Earthís terrestrial North pole and so all the stars in our sky appear to circle the North Star every 24 hours in response to the Earthís 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 a 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 start out evenings higher and higher in the sky as the stars of Orion and his gang start lower and lower in the west. It looks as if the mighty lion is chasing Orion and his gang out the night sky. This is due to the Earthís 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 the lesser vibrant constellations of spring. Enjoy the winter constellation while we still have them!
The full moon this month is on March 9th and leading up to that date, thereíll be much moonlight in the evening sky making it tough for hardcore stargazing. The full moon this month is also considered a ďSupermoonĒ since itís physically a little closer to Earth than average making it slightly larger and brighter.
The planet Venus still dominates the early evening western sky and is by far the brightest star-like object seen in the night sky this month. On March 24th, it reaches its highest evening altitude. Because of this, Venus is available in the evening sky for nearly four hours before it slips below the horizon. Venus is so bright not only because itís so close to the Earth but also its of its very reflective cloud cover, bouncing a lot of sunlight our way.
Since Venus is completely cloud covered, the only thing that makes Venus worth checking out with a telescope is that just like the moon, it goes through phases. This month it resembles a first quarter (half-moon). Both Venus and Mercury go through phase shape changes like our moon because their orbits around the sun lay within Earthís orbit. This results in a gradual, continual change in the sun angle between the Earth, Sun, and Venus.
You will want to use your telescope or even a pair of binoculars on Venusís Sunday evening, March 8th. That when Venus and the distant planet Uranus will nearly in the same line of sight. You should easily spot Uranus. Itíll be the next brightest star-like with a bit of a greenish tinge, less than three degrees to the upper right of Venus. Thatís about the width of three of your fingers held together at armís length. Uranus is just over 1.9 billion miles away. The light from Uranus takes nearly three hours to reach Earth this month!
If youíre an early riser, you can see four planets this month. Theyíll be crowded together in the early morning southeastern sky, just before morning twilight. During the first half of March, youíll see three of them near the horizon in a tight diagonal parade line. From lower left to upper right, they are Saturn, Jupiter, and Mars. Jupiter by far is the brightest of the three.
In the latter half of March, Saturn, Jupiter, and Mars will draw even closer together in the southeast sky with Mercury joining them to the lower left. Itís going to turn into quite a show. On March 18th, the waning crescent moon joins the fray. The moon, Mars, and Jupiter will form an exceptionally tight triangle in a very close celestial conjunction. The next morning, March 19th, the thinner waning crescent moon will be parked just to the lower left of Saturn. Then on March 20th Mars and Jupiter will pass within one degree from each other. Now thatís a celestial hugging!
On March 21st, Mercury will be joined by an extremely faint and thin waning crescent just below and to the right of the planet named after the messenger of the gods.
Finally, on Tuesday morning, March 31st, Mars and Saturn will pass within a degree of each other in the very low morning southeast sky.
A lot is going on this month
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul, and is author of the book, ďStars, a Month by Month Tour of the ConstellationsĒ 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 youíre seeing in the night sky drop me a line at firstname.lastname@example.org