What is a comet?
Comets are often referred to as “dirty snowballs.” They are left over from the formation of stars and planets billions of years ago. Before zipping around the Sun with their characteristic big tails, comets that we see in our solar system start out as big chunks of rock and ice just floating around in something called the Oort Cloud. When the gravity from a large passing body, like a star, becomes strong enough, some large chunks of ice get pulled away from the cloud and head toward the Sun. As that ball of ice gets close enough to the Sun, its heat begins to melt some of the ice that makes up the comet. The melted ice becomes a gaseous tail that extends away from the source of the heat (in this case, the Sun). The tail is pushed out by the Sun’s solar wind. What keeps the comet in motion and guides its path is the gravity from all the planets and stars it passes. When a comet is in our solar system, most of the gravity affecting the comet’s motion is due to the Sun. As a comet gets cl
Take a deeper look into our solar system and discover exactly what a comet is with VideoJug’s help. Comets are often referred to as ‘dirty snowballs’. They are what is left over after the formation of the stars and planets billions of years ago. They live in an area of space outside the orbit of Pluto called the Oort cloud, named after the Dutch Astronomer Jan Oort who first proposed its existence in 1950. The Oort cloud is an immense spherical cloud surrounding our solar system; its vast distance is considered to be the furthest edge of the Sun’s gravitational effect. Comets are usually made of chunks of frozen gases, rock and Ice. They are not very big compared to a planet or Moon, the largest being perhaps a few hundred kilometres across but most being less than a kilometre. Millions of Comets usually live peacefully in this Oort cloud, orbiting around the Sun, billions of miles deep into Space. But every now and again one of them may get disturbed in its orbit and begin to fall in
A comet is a dirty snowball. A comet is an icy mud ball. A comet is a demon in the sky! At least that’s what some ancient and even recent observers imagined. Comets, from the Greek (aster) kometes meaning long-haired (star), have been observed for thousands of years. The Europeans documented the 1066 AD apparition of Comet Halley in the Bayeax Tapestry, while the Chinese have observations of Comet Halley going back to 240 BC! However, it wasn’t until 1705 when Edmond Halley predicted the return in 1758 of a particular comet that astronomers realized that comets were objects far out in the solar system rather than vaporous demons in the atmosphere.
IN the first place, are comets composed of solid, liquid, or gaseous substances? Are they something, or the next thing to nothing? It has been supposed by some that they are made of the most attenuated gases, so imponderable that if the earth were to pass through one of them we would be unconscious of the contact. Others have imagined them to be mere smoke-wreaths, faint mists, so rarefied that the substance of one a hundred million miles long could, like the genie in the Arabian story, be inclosed in one of Solomon’s brass bottles. But the results of recent researches contradict these views: Padre Secchi, of Rome, observed, in Donati’s comet, of 1858, from the 15th to the 22d of October, that the nucleus threw out intermittingly from itself appendages having the form of brilliant, coma-shaped masses of incandescent substance twisted violently backward. He accounts for these very remarkable changes of configuration by the influence first of the sun’s heat upon the comet’s substance as
