Different Constellations in the Northern and Southern Hemisphere
There are many constellations that can be seen in both the northern and southern hemispheres; however, each hemisphere hosts some constellations that are visible only in one or the other.
As Earth orbits the sun, the constellations in the night sky shift as well. Different seasons and times of the year determine which constellations are visible. There are also constellations that are unique to the northern or southern hemisphere, called circumpolar constellations. Circumpolar constellations are useful reference points for navigation because they never rise or set. The constellations that don’t move can also help in locating the seasonal constellations such as the constellations that make up the zodiac.
If you are looking for constellations that are visible during a specific season, sky maps can help you. Some of the most popular circumpolar constellations in the northern hemisphere are:
- Ursa Major (Great Bear/Big Dipper)
- Ursa Minor (Little Bear/Little Dipper)
Some of the most well-known southern circumpolar constellations include:
Orion is a constellation that is usually always visible in both the northern and southern hemisphere. For many years, people who traveled by sea were dependent on Orion and the other circumpolar constellations to help guide them.
Now that you know more about the seasonal and circumpolar constellation, we’ll take a closer look at the constellations in the northern hemisphere.
Major Northern Hemisphere Constellations
Even though technology has made it much easier for people to find their way, especially with the invention of GPS, and GPS for Smart Phones, navigating by the stars is still a great skill to have, and it can be a lot of fun. Not only can it be interesting, but it could also possibly help you in a critical situation if you found yourself without a working phone, in an area that is unfamiliar. Using the stars, you can locate North, South, East, and West
Polaris, the North Star
If you are looking for the North, you will want to find Polaris because it is the North Star. If you know where to find the big and little dipper, you will be able to find it. While the North Star is part of the Ursa Minor, or Little Dipper constellation, it is usually easier to locate the big dipper and use it to track the Little Dipper. The North Star is the easily found within the Little Dipper because it is the brightest star of that constellation, and is located in the handle.
The North Star is called Polaris because it is located within one degree of the North Pole and therefore does not appear to move with the rotation of the Earth.
Ursa Major, the Big Dipper
Ursa Major, also called the Big Dipper, is usually a pretty easy constellation to locate, depending on the time of the night and your location. The name Ursa Major translates in Latin to “greater she-bear.” It was named Ursa Major because the people of ancient Greece believed the big dipper looked like a big bear. Over time, people associated Ursa Major with a large water dipping spoon, and that’s why it is called the Big Dipper.
If you are looking at the ladle part of the big dipper, the star that is located on the bottom of the dipper, and furthest from the handle, is the one you can use to find Ursa Minor. If you are looking at that star, you can move your eyes to your right and angled upward, and you will see Ursa Minor.
Ursa Minor, the Little Dipper
Known most popularly as the Little Dipper, Ursa Minor actually nicknamed the Little Bear, for the same reason ancient Grecians called Ursa Major “Big Bear.” Once you have located Ursa Minor, you can find the North Star because it is the last star on the top of the handle on the Little Dipper.
Cepheus, the King
Cepheus constellation is known as one of the Greek constellations. Named after the mythical King of Aethiopia, Cepheus was the husband of Cassiopeia and the father of Andromeda. All three-mythical people are constellations located right by each other and are all part of the Perseus family.
One of the most significant stars in the Cepheus constellation is the Garnet Star. The Garnet Star is known because it is one of the largest known stars of the Milky Way.
Cassiopeia, the Queen
Named after Cassiopeia, the mythical vain queen in Greek mythology, the Queen constellation is also part of the Perseus family. Cassiopeia was wife to Cepheus, and the constellation was charged by the Greek astronomer named Ptolemy during the second century. Ptolemy charted all of the Perseus family except for Lacerta.
Many people can easily find Cassiopeia in the northern night sky because it is shaped like a “W.”
Draco, the Dragon
Draco constellation is the eighth largest constellation in the sky, and like the constellations of the Perseus family is located only in the northern hemisphere. In Latin, Draco means “the dragon,” and is a representation of Ladon, the Greek mythological dragon who guarded the gardens of the Hesperides.
Also, like the dragons of the Perseus family, Draco was also cataloged by Ptolemy in the second century. For most people in the northern hemisphere, Draco never disappears below the horizon.
If you know some of the major constellations of the northern hemisphere, it can help you to more easily navigate the night sky.
How to Navigate by the Stars in the Northern Hemisphere
While many people enjoy pointing out the major constellations and knowing some of the most prominent stars, there is actually a lot more to navigating the sky. Here are some of the essential things to know for navigating by the stars in the northern hemisphere.
Finding the North Star
As discussed above, finding the North Star is vital because it helps you know which way is north. Polaris, the North Star, does not move and is always within one degree of the celestial north pole.
It is a common belief that the North Star is the brightest one in the sky, which is not the case; However, the North Star is the brightest star in the Ursa Minor constellation. A brief recap of finding the North Star is to start by finding Ursa Major the Big Dipper, and locating the star that is on the bottom of the dipper spoon, and not touching the handle. Once you discover that star, move your eyes at an angle to find the Little Dipper or Ursa Minor. The top star on the handle of the Little Dipper is the North Star.
Finding Your Latitude
After you see the North Star, you can find your latitude. If you are looking at stars for fun and want to find your latitude, it is easiest to accomplish if you have a sextant or a quadrant because those tools help you read the angle between the North Star and the northern horizon.
If you don’t have any tools, you can still find the latitude by extending your fist toward the horizon and then placing your fists hand-over-hand up to the North Star. Every fist you make is approximately ten degrees.
For many people, the North Pole is known as North; However, there are actually two north poles. One is the geographic north pole, and the other is the magnetic north pole. When you use a compass, the needle points to the magnetic north pole.
There are two different north poles because the magnetic field that surrounds the Earth has a north and south pole which is the end of the magnetic field. The magnetic field does not line up correctly with the axis that the Earth spins around. Because of that, there are two north poles and two south poles.
Magnetic declination is the difference between the magnetic north pole and the geographic north pole. The angle of the magnetic declination is different depending on where you are located. In some parts of the world, the declination is very small, while other parts can see a reasonably big angle.
Most of the time, magnetic declination and following true North is not necessarily significant, however, for someone who is trekking the globe and needs to follow True North, a compass will not work because it will guide to the magnetic North pole.
If you were exploring at night and needed to head true North, finding and following the North Star is how you would go.
To find South using the stars, you will need to spot the constellation, Orion. Orion is known as the Hunter and looks like a bent hourglass. Orion is made up of several well-known stars including:
- Betelgeuse and Bellatrix which represent Orion’s shoulders.
- Saiph and Rigel, Orion’s knees or feet.
- Alnitak, Alnilam, and Mintaka are the stars the make-up Orion’s belt.
The constellation Orion is best seen in the northern hemisphere in the winter and early spring, but it can be seen late night in the fall and right before dawn in the summer.
Once you find Orion, you can try to find its sword which points South. If you locate the star Alnilam, which is the middle star in Orion’s belt, you will see one bright, one fuzzy, and one dim star hanging down from the belt. Orion’s sword points to the South.
One neat tip about the stars in Orion’s belt, the star that looks fuzzy is actually a nebula called the “Great Nebula of Orion,” and it is considered to be an interstellar nursery because new stars are being formed there.
Finding East and West
When you are looking at Orion’s belt, the rightmost star on its belt is the one called Mintaka. The star Mintaka always rises and sets within one degree of True East or True West.
Navigating the northern hemisphere is sometimes considered easier than navigating the southern hemisphere because the northern hemisphere has a bright and easy to find North star; however, navigating by the stars can be simple no matter where you are if you know where to look.
Important Southern Hemisphere Constellations
While there are several more well-known circumpolar constellations in the northern hemisphere, there are three major constellations in the southern hemisphere. Here are the details about constellations Carina, Centaurus, and Crux.
Carina is a southern hemisphere circumpolar constellation. Its name is Latin and means “the keel,” referencing the keel of a ship.
When the Greek astronomer, Ptolemy, first charted Carina in the second century, he included it as part of a very large constellation he named Argo Navis. In the eighteenth century, a French astronomer named Nicolas Louis de Lacaille divided the Argo Navis constellation into three much smaller constellations – Carina, Vela, and Puppis. The three constellations were finally added to the official record of modern constellations during the early twentieth century.
One of the stars that make up Carina is the second brightest star in the sky, named Canopus.
Centaurus constellation is another one of the Greek constellations and is also one of the largest constellations in the whole sky. Centaurus is named because it represents the centaur of Greek mythology, the half horse, half man creature.
Centaurus contains two stars that are among the brightest ten in the sky, named Alpha Centauri and Beta Centauri.
Crux constellation is also known as the Southern Cross, and it is an essential constellation in the southern hemisphere. While it is the smallest constellation of all 88 recorded constellations, it is one of the most well-known and is significant for navigation.
The Crux is especially prominent in both New Zealand and Australia and can be seen all year there. For other people in the southern hemisphere, Crux is not visible everywhere, but it never sets below the horizon.
Navigating the Southern Hemisphere Using Stars
In the northern hemisphere, Polaris is significant for finding True North. Once you cross the equator, you will no longer be able to see the North Star. The southern hemisphere has a different set of stars to depend on for navigation.
While there is a star, called Sigma Octantis, that is similar to Polaris because it sits very close to the South Pole, it is too dim to see. Instead, most people navigate through a different constellation.
Known as the Southern Cross, a group of stars that form the Crux constellation are significant for navigation. The Southern Cross constellation is so significant in the southern hemisphere that it is placed on the national flags of several nations like Australia, New Zealand, and Brazil.
Southern Cross is a group of five stars, four of them being the brightest, that form a cross in the sky.
To navigate, you need to know the star names that make up the Southern Cross. The star at the top of the cross is Gamma Crucis, or Gacrux. The star at the bottom of the cross is Alpha Crusis, or Acrux. The stars that make up the arms of the cross are Beta Crusis, or Becrux, and Delta Crucis. The small star in the middle of the cross is called Epsilon.
When you are looking at the Southern Cross, you can find south by using your hand to draw a line from Gacrux to Acrux and then extending that line about 4.5 times more. The end of the line is close to the southern celestial pole. From there, you can draw another line down to the horizon. At that point, your body will be facing the proper direction and east will be to your left, west to your right, and north will be behind you.
Additional Tips and Final Thoughts
The continued advances in technology have made it easy for most people to navigate the world with their smartphones and GPS systems. Navigating by the stars is no longer a necessity like it was for many centuries. Now, people who understand how to navigate the night sky typically just do it for pleasure.
One final tip to help you if you are ever lost and need to find you way is to find your direction by following a star’s position. You can do it from anywhere. Here is how:
- Step 1: Put you stakes (or sticks) in the ground about a yard apart.
- Step 2: Pick any star you want. It is usually easiest if you pick a bright star.
- Step 3: Move around until you have both stakes in line with the star you chose.
- Step 4: Once the star moves out of alignment with the stakes, you will be able to tell which direction you are facing. If the star rose higher than the stakes, you are facing east. If the star moved below the stakes, you are facing west. If the star moved left of the stakes, you are facing north, and if the star shifted to the right of the stakes, you are facing south.
Whether you are navigating for fun or necessity, understanding the major constellations and stars in the northern and southern hemisphere can help guide you through the night to your destination.