Sara L. Latta - Exploring Constellations

The word constellation comes from the Latin word constellatio. It means, set of stars.

Stars are giant balls of hot gas. They make energy. We see that energy as light. Stars come in different sizes and colors. Our sun is a medium-sized yellow star. Stars that are larger than the sun are blue. They are very hot. Stars that are smaller than the sun are red. They are less hot.

Galaxies are made of stars. They are also made of clouds of gas and dust. We live in a galaxy called the Milky Way. If the sky is dark enough, you can see part of it. It looks like a cloudy white streak across the sky. The ancient Romans called it the Road of Milk.

Some stars look close together in the night sky. In reality, they may be very far apart. One of the most familiar constellations is Orion. It is named after a hunter in Greek away from each other. The two brightest stars in Orion are 400 light-years apart! Some look bright because they are closer to Earth. Others look bright because they are very large stars, but the naked eye cant see the difference.

Earth turns on its with each season.

Some constellations appear close to Earths poles. These are constellations. People living in the Southern Hemisphere can see constellations near the South Pole all year. People living in the Northern Hemisphere can see constellations near the North Pole the year round. The lucky ones are the people living near the equator. They can see all of the constellations in the sky throughout the year! The constellations may appear high or low in the sky, depending on the season, but they are always there.

Most constellations are not near the poles. You can only see them during certain times of the year. They are seasonal constellations. You can see some of these constellations in both hemispheres.

Around 5,000 years ago, Middle Eastern astronomers studied the stars and planets. They watched their positions and movements through the night sky as the seasons changed. They used this information to make calendars. These calendars helped farmers know when to plant their seeds. Travelers used the positions of the stars to guide them on their journeys.

Egyptian calendar

These ancient astronomers had another reason for studying the night skies. They believed that the movements of the stars could help them understand the will of their gods. The planets, sun, and moon seemed to pass in front of a different constellation every month. Now we know that it is the other way around. As Earth the sun, we look into space in different directions. That is why we see different constellations throughout the year.

These constellations became known as the .

Astronomy or Astrology?

Although astrology and astronomy have a shared history, they are very different. is the scientific study of everything in outer space. Astrology is the belief that the movements of the stars and planets affect people and events on Earth. It is not a science.

Did You Know?

The word Zodiac means circle of little animals.

CIRCUMPOLAR CONSTELLATIONS IN THE NORTHERN SKY

There are many constellations visible in the Northern Hemisphere year round. Ursa Major, also called Great Bear, is one of them. It is one of the most famous constellations in the Northern Sky. Its seven brightest stars form a feature you may know: the Big Dipper. The Big Dipper is not a constellation. It is an . The two stars on the outer edge of the dipper point directly to the North Star. Sailors used the North Star to find their way at sea. It was always in the north. It can help you figure out which way is north too!

Many cultures told stories about Ursa Major. The ancient Romans said that it was a beautiful woman named Callisto. They said a jealous goddess changed Callisto into a bear.

The tail of Ursa Minor, also called Little Bear, curves toward Ursa Major. The tail looks like a smaller version of the Big Dipper. People sometimes call it the Little Dipper. The North Star is at the very tip of its long tail. Roman legend says that Ursa Minor is Callistos son. He was also turned into a bear.

Cassiopeia is shaped like a W (or an M, depending on the time of year). The constellation appears as a queen sitting on a chair, combing her hair.

Draco represents a dragon that was killed by the Greek warrior Hercules. Dracos body curls like a snake across the sky. It lies between Ursa Minor and Ursa Major.

CIRCUMPOLAR CONSTELLATIONS IN THE SOUTHERN SKY

Crux is the smallest of the 88 constellations. It points the way to the South Pole. It can help you figure out which way is south. The four brightest stars form the Southern Cross. They look like a kite.