Signs of Spring in the Night Sky

Vintage star chart illustration features the constellation Hydra.
Historic star chart etching features the constellation Hydra.

Public domain / Sidney Hall (1788 - 1831), British cartographer and engraver

Winter wanes with the arrival of March winds, and the vernal equinox signals the spring season. The crocus blooms. Robins sing. Plants gleam newly minted green. Spring is a time of new beginnings.

The spring night sky also brings signs of change. Constellations that were visible in winter give way to different celestial features. Ancestral people observed and documented these seasonal patterns through time. They named the forms they saw in the sky, and created stories based on their observations of celestial and seasonal patterns. In this way, knowledge was preserved for successive generations. From the hundreds of constellations documented, the International Astronomical Union finalized the list at 88 in 1922. The constellations we know today feature a cast of mythological characters that include land animals, water creatures, men, women, and centaurs.

What to See


Good stargazing experiences ideally begin with a naturally dark night sky. National park settings—even those near cities—provide optimal views to the night. The National Park Service recognizes the night sky as more than a pretty sight; it is part of a complex ecosystem that supports both natural and cultural resources. The NPS works to conserve this resource because it is important to ecosystem function, the setting of historic and cultural parks, and the quality of visitor experience.

Celebrate the spring season by soaking up starry views away from city lights. Whether you are an old hand at spotting constellations or just beginning to learn, the following astronomy tips will help orient your night sky experiences.

“When we try to pick out anything by itself, we find it hitched to everything else in the universe.” — John Muir

Illustration shows the Big Dipper in relation to the Little Dipper in the spring night sky.
Illustration shows the Big Dipper in relation to the Little Dipper in the spring night sky, as seen in the north side of the night sky, Northern Hemisphere.

NPS

The Big Dipper


Of all the night sky attractions, the Big Dipper is among the most known and recognized by kids and grownups alike. As its name implies, it resembles a ladle or dipping bowl with a handle. It appears highest (and upside down) in the night sky during spring. You can easily find it in the early evening. The Big Dipper is actually not a constellation but an asterism—a small grouping, or pattern, of stars. It is located within the constellation Ursa Major, “The Big Bear.”

Asterisms can help you find larger constellations. You can use the Big Dipper to find the Little Dipper, an asterism within the constellation Ursa Minor, “The Little Bear.” Connect the dots between Merak, a star that anchors the outside bottom of the Big Dipper’s bowl furthest away from the handle, and Dubhe, the star above. Extend a straight line five times the distance from Dubhe, and you’ll see the North Star, Polaris. Earth’s axis points to Polaris. Located above the North Pole, the star does not rise or set but stays in the same position. From there you can find the Little Dipper near to the horizon, with Polaris at the end of its handle.

Illustration shows location of the spring triangle asterism in relation to constellations.
Illustration shows location of the spring triangle asterism in relation to other constellations, including Bootes, Leo, Virgo, and Hydra. Constellations are visible in the south side of the night sky, Northern Hemisphere.

Photo courtesy of Creative Commons / Wikipedia

The Spring Triangle


You can also use the Big Dipper to find the Spring Triangle, an asterism that, appropriately named, is best seen in spring. The Spring Triangle is composed of three brightly shining stars: Regulus, the brightest star in the constellation Leo, “The Lion”; Spica, the brightest star in Virgo, “The Maiden”; and Arcturus, a fiery red star in the constellation Boötes, “The Herdsman.”

You can find Regulus, and thus the other stars and constellations in the Spring Triangle, by first locating the Big Dipper’s stars, Megrez and Phecda (also known as Phad). Trace a straight line from Megrez, at the top of bowl on the handle side, to Phecda below. Continue straight through until you see a brightly shining star at the bottom of a star pattern forming an inverted question mark. This star is Regulus, one of the points of the Spring Triangle. The question mark forms the head of the constellation Leo.

Illustration shows close up excerpt of the Leo constellation in spring from the vantage of facing the south side of the night sky, Northern Hemisphere.
Illustration shows close up excerpt of the Leo constellation in spring, with the head visible by the inverted question mark.

Illustration courtesy of Creative Commons / Wikipedia

Regulus / Leo


You may have heard the expression, “March comes in like a lion.” The lion in the Zodiac constellation Leo is first seen in spring around the time of the March equinox. Seated in repose in the night sky, Leo is among the more easily recognizable constellations. Just as the lion is known as “King of the Beasts,” Regulus is considered to be “King of the Stars” among the six that define it, and shines brightly in the place that mark’s the lion’s heart. The curve of the backward question mark above Regulus forms Leo’s head. A small triangle of stars defines Leo’s tail, with the star Denebola at the rear. Denebola is also part of a near perfect equilateral triangle within the larger Spring Triangle. (See full graphic version above.)

Leo is considered to be one of the oldest documented constellations, with descriptions dating to many ancient cultures, including Babylonia, Syria, and Mesopotamia as early as 4000 BC. It is at its highest point in the night sky in early April around 10 p.m., sinking lower in May at 8 p.m. By late summer, Leo sets with the sun on the horizon.

Illustration excerpt shows constellation Bootes in relation to Ursa Major.
Illustration excerpt shows the constellation Bootes and the star, Arcturus, in relation to Ursa Major, as seen in the north, spring night sky, Northern Hemisphere.

Image courtesy of Creative Commons / Wikipedia

Arcturus / Boötes


In Greek mythology, the star Arcturus is known as the “bear guardian.” According to legend, Hera, the jealous wife of Zeus, transformed Callisto, her husband’s lover, into a bear. Callisto was nearly shot when her son, Arca, was out hunting one day and did not recognize the bear as his own mother. She was spared by Zeus, who placed both mother and son in the night sky. Callisto is associated with Ursa Major, the Great Bear constellation. Her son, the star Arcturus, follows his mother close behind, keeping watch in the constellation Boötes, the herdsman.

Recognizable for its glowing, red-orange color, you can find Arcturus by drawing a line from Regulus through to Denebola on Leo's tail and straight to this bright attraction, which anchors the opposite side of the Spring Triangle. Another way is to continue the line of the curve in the Big Dipper’s handle through its last star, Alkaid, and then on to Arcturus. It is the brightest star in the Northern Hemisphere, the fourth brightest in the night sky, and the brightest star in the Boötes constellation. The mythical oxen led by Boötes are yoked to the polar axis, which keeps all celestial bodies in working, ordered rotation.

Illustration shows excerpt view of the constellation Virgo and star, Spica.
Illustration shows excerpt view of the constellation Virgo and its star, Spica, as seen in the north side of the night sky, Northern Hemisphere.

Image courtesy of Creative Commons / Wikipedia.

Spica / Virgo


Virgo the maiden is the second largest constellation in the sky (after Hydra; see below). The blue-white star Spica is its brightest star, and among the top 20 “first magnitude,” or brightest stars, in the entire night sky as ranked by Hipparchus in the 1st century BC. First magnitude stars shine 100 times brighter than, say, 6 magnitude stars, which are barely visible to the naked eye. Twice the size of the sun and located 260.9 light years away from Earth, Spica shines with an intensity that is 2,300 times brighter than the sun. It is actually a binary star—two stars that revolve around each other so closely, they appear as one.

Spica is located between Argulus and Regulus in the Virgo constellation. It appears in the maiden’s left hand. The Latin name for Spica is “ear of grain.” Greek myths identify Virgo as Demeter, goddess of grain. Many star charts show her holding a sheaf of wheat. Virgo appears in the early spring during planting season with both feet “on the ground” of the eastern horizon. She departs after harvest in early autumn.

Illustration shows the star pattern that forms the constellation Hydra
Illustration shows the star pattern that forms the constellation Hydra, the water snake that hugs the horizon of the north night sky in spring, Northern Hemisphere.

Image courtesy of Stellarium

Hydra


Winding at the base of the Spring Triangle is Hydra, the water serpent, another feature attraction in the spring night sky and the largest of the 88 constellations. Identified by Ptolemy, a Greek astronomer in the 2nd century, Hydra’s long body shimmers with faintly shining stars. Best visible in the Northern Hemisphere in the months of March through May, Hydra can be found below Spica and Virgo, and Regulus and Leo. According to Greek legend, Hydra was a multi-headed monster that was killed by the hero Hercules and laid to rest in the night sky.

Now you Know!


With a little information, the night sky can be a familiar place. Now that you have learned how to find some of the stars, asterisms, and constellations in the spring night sky, the National Park Service hopes you will enjoy putting your newfound skills into practice. Happy Equinox!

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Article by Julie West, communications specialist, Natural Sounds and Night Skies Division