What is the difference between a star and a planet?

The difference between a star and a planet lies in their formation, size, and the way they emit light. A star is a massive celestial body that is made up of gases, mostly hydrogen and helium, and emits light and heat through nuclear fusion. In contrast, a planet is a celestial body that orbits a star, is spherical in shape, and does not emit light of its own.

Stars are formed from the gravitational collapse of gas and dust in space, which causes the gases to heat up and become dense enough for nuclear fusion to occur, releasing energy in the form of light and heat. Planets, on the other hand, are formed from the leftover materials that did not become a star during the process of star formation, known as protoplanetary disks.

Stars are much larger and more massive than planets, ranging from small ones that are a few times larger than Jupiter to massive ones that are hundreds of times larger than the Sun. Planets, on the other hand, are much smaller, with sizes ranging from that of the Earth to that of Jupiter and beyond.

Finally, stars emit light of their own, whereas planets do not. Planets reflect light from their parent star, which is why they are visible in the night sky. The light that a planet reflects can help astronomers determine the planet's composition, temperature, and other characteristics.