The main difference between constellation and galaxy is that constellation is a recognized pattern of stars in the night sky, while a galaxy is a system of billions of stars, together with gas and dust, held together by gravity.
Both terms constellation and galaxy are related to stars, but constellations are not real objects while galaxies are. Constellations are imaginary patterns. A galaxy, on the other hand, is made up of gas, dust, billions of stars, and their solar systems.
Key Areas Covered
1. What is a Constellation
– Definition, Features
2. What is a Galaxy
– Definition, Features
3. What is the Difference Between Constellation and Galaxy
– Comparison of Key Differences
Key Terms
Constellation, Galaxy
What is a Constellation
A constellation is a recognized pattern of stars in the night sky. In other words, it’s a group of stars that appears to form a picture or pattern. In fact, the word constellation comes from Latin constellacio, which means a set of stars. These have imaginary boundaries -boundaries we make by connecting the dots. We can see different constellations at different times of the years. The constellations you see in the sky may also differ according to your location. Furthermore, the International Astronomical Union has recognized 88 constellations. Orion, Canis Major, Ursa Major, Ursa Minor, Gemini, Lyra, Capricornus, and Draco are some examples.
It’s important to know that constellations are not real objects’. They are only patterns we can see from our position on Earth. Stars in a constellation may appear to be very close to each other, but in reality, they may have no real connection and have large distances in space. However, constellations have proved to be a helpful way to identify the position of stars in the sky.
What is a Galaxy
We can define a galaxy as a collection of billions of stars, their solar systems, gas and dust, all held together by gravity. Our planet, Earth, is a small part of a solar system. It orbits around the Sun. The Sun is only a star among the billions of stars in the Milky Way Galaxy. There are billions of such galaxies in the universe. When scientists looked at a small patch of space with the Hubble Space Telescope, they were able to find 10,000 galaxies with different shapes, colours, and sizes.
Although the Milky Way Galaxy is huge, our neighbour, the Andromeda Galaxy, is even huger. The Milky way is spiral-shaped. There are other galaxies with this shape, with curved arms that make them look like a pinwheel. There are also galaxies with a smooth, oval shape. We call these elliptical galaxies. In addition to these, there are galaxies that do not fall into both these categories. Their shape is irregular, and they look like blogs. Sometimes, galaxies can get close and smash into each other. About five billion years from now, the Milky Way will smash into Andromeda. However, galaxies are so large and spread out they even if they smash into each other, the solar systems and planets in them won’t come close to colliding.
Difference Between Constellation and Galaxy
Definition
A constellation is a recognizable pattern of stars in the night sky, while a galaxy is a system of billions of stars and their solar systems, gas, and dust, held together by gravity.
Concept
Moreover, the constellation is an imaginary pattern, while the galaxy is a real concept.
Examples
Orion, Canis Major, Ursa Major, Ursa Minor, Gemini, and Lyra are some examples of constellations, while the Milky Way, Andromeda, and Triangulum Galaxy are some examples of galaxies.
Conclusion
A constellation is a group of stars that appear to form a pattern in the night sky, while a galaxy is a system of billions of stars and their solar systems, gas, and dust, held together by gravity.
Image Courtesy:
1. “Constellation Centaurus” By Till Credner – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Andromeda Galaxy (with h-alpha)” By Adam Evans – M31, the Andromeda Galaxy (now with h-alpha)Uploaded by NotFromUtrecht (CC BY 2.0) via Commons Wikimedia
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