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What is a comet? |
Space
A comet is one of many objects in space that share our solar system with us. They are made of rock, dust, frozen water (ice!) and other frozen gases. It’s so cold in space that these gases can actually freeze into a solid form! Comets also have long tails made of dust and gases that are lit up by energy from the Sun!
Comets are not as big as planets, but they are big compared to you and me! The smallest ones are about the size of a football field, but the biggest ones can be as large as 25 miles across—and that’s not including their tails!
They travel around the Sun just like the Earth does, but often the path of a comet is a huge oval that might only pass the Sun once every few years, once every few hundred years, or even once every few thousand years! Some trips around the sun for comets can take even longer than that! Some comets may only pass the Sun once and then escape the Sun’s gravity and never return!
Most of the comets in space aren’t bright enough to be seen just with just our eyes. Every so often, one will light up especially brightly so that we can see it. These are called “Great Comets”!
Great Comets are rare. Decades can pass between them, though sometimes only a few years. One of the most famous of these comets is Halley’s Comet. This bright comet has a path around the sun that takes 75 to 76 years. It last appeared in 1986, so its next appearance should be in the year 2061! How old will you be the next time Halley’s Comet passes?
There will probably be several more Great Comets in the sky before Halley’s comes around again, but these are not easy to predict. They always make the news when they appear, so keep an eye out for these in headlines and in the skies!