TRAVELING in an elongated orbit around the Sun is called a comet.When a comet’s orbit comes close to the sun, the ice in its central nucleus turns into gas that shoots out of the comet’s sunlit side, carried by the solar WIND outward to form into a long tail.Halley's comet is a short-period comet visible from Earth every 75–76 years. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. Satellite:A satellite is an object in space that orbits or circles around a bigger object.There are two kinds of satellites: natural (such as the moon orbiting the Earth) or artificial (such as the International Space STATION orbiting the Earth).Star:STARS are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores.Aside from our sun, the dots of light we see in the sky are all light-years from Earth.