10 Differences between stars and planets

Stars and planets are both huge astronomical bodies held together by their own gravity. Since they are both astronomical bodies, it becomes important to distinguish them from each other. The main difference between the stars and planets is that stars undergo nuclear reactions and release massive amounts of energy. There are also other differences like size, temperature, etc. In this article, we discuss 10 differences between stars and planets.

difference between stars and planets
Difference between Stars and planets

Differences between Stars and Planets

We can roughly differentiate between the stars and planets with our naked eyes. We can see that the sun (a star) is huge compared to other planets. The temperature of the stars is very high compared to that of the planets. Star produces light and is radiant while planets do not produce light. Planets seem to be solid, while stars seem to be gaseous. Let us look a little more in detail at the differences between stars and planets.

SnOBasis for differentiationStarsPlanets
1DefinitionStars can be considered as plasma, consisting of a mixture of gases undergoing continuous nuclear reactionsPlanets are celestial objects with masses that revolve around a star.
2TemperaturesStars have very high temperatures due to the nuclear reactions occurring inside them. For example, the Sun has a temperature of 5,505 °C. Planets have low temperatures. The temperature might be affected by the distance from a nearby star.
3SizeStar is huge in size compared to planetsPlanets have a smaller size compared to the planets
4LightStar is capable of producing its own light. They are composed of gases that undergo nuclear reactions to produce light and heat.Planets do not produce their own light.
5Twinkling effectStars possess a twinkling effect Planets do not show the twinkling effect
6Number in our solar systemThere is only one star in our solar systemThere are 8 planets in our solar system
7ShapeSince they are not solid they do not have definite shapes, can be considered as dots.Spheroids
8CompositionStars are composed of light elements like Hydrogen, Helium, etcPlanets are composed of a combination of solids, liquids, or gases.
9OrbitEach star orbits its galaxy’s center Planets usually orbit the star in the solar system.
10SpeedStars have a high speed compared to planetsPlanets have a low speed compared to planets

Now let us now discuss the differences between stars and planets one by one in detail:

Stars are composed of gases that undergo continuous nuclear reactions and hence, they are radiant and have the light of their own, but on the other hand, planets are not gaseous and they are a mixture of gases, liquids, and solids and they do not have the light of their own.

Stars have a very high temperature due to the continuous nuclear reactions inside them for example, the sun has a temperature of 5,505 °C, on the other hand, planets have very low temperatures. Some planets have high temperatures due to the close proximity to a star and the that are further away from the star have very low temperatures.

Size comparison of our star(Sun) with other planets Image by Comfreak from Pixabay 

Stars are very huge compared to planets. For example in our solar system, the Sun has a radius of 696,340 km compared to a radius of 6,371 Km of earth. This means the sun has a diameter that is almost 109 times greater than that of Earth.

Nuclear reactions are always followed by the production of heat and light so these stars have very high temperatures and produce light. On the other hand, planets do not have the light of their own.

When we see stars in a clear dark sky we can see them twinkling. Stars process a twinkling effect but planets do not show any twinkling effect.

Planets generally do have a definite shape and are generally spheroids but stars on the other hand are gaseous and are shaped like a dot. For example, our Earth is a spheroid. 

Shape comparison between our planet Earth(left) and stars(rights). Earth appears to have an ellipsoid or spheroid kind of a shape while stars appear as dots in the sky.

Stars are composed of elements like Hydrogen and Helium which are very light elements with atomic numbers of 1 and 2 and planets are composed of a combination of solid-liquid and gases.

Stars look to be stationary but they also move at high speeds. Each star orbits the galaxy center like for example the sun in our solar system also orbits around a specific location in the galaxy. On the other hand planets orbit around a star.

Stars have a very high speed compared to the speed of planets. For example, the speed of the sun is 200 Km/s compared to around 30km/s of Earth.

See also