Why do Comets have tails?

The Comets are made up of a mixture of rock, dust and ice. This is why astronomers also call it a ‘dirty snowball’. When comets move closer to the sun, the ice evaporates and remains hung as a cover of gas and dust around the comet. This is blown away by the solar wind, a stream of electrically charged particles, so that it gives rise to a long tail. This is also known as the coma. A few comets can be seen regularly from the Earth, while the others never come near our planet.
For instance, the Halley’s comet comes near the Earth’s orbit after each 76 years. It was last seen in our beighbourhood in 1986 and will come again near us in 2062, Insha Allah.