What is a sight that is seen once in 76 years? C’mon, I know you know it… Right, the Halley’s Comet, it wasn’t so hard, was it? But why the Halley Comet can be seen only once in 76 years? Because its orbit around the Sun is significantly expressed at the moment its location is closest to the Sun, when it’s located betweenVenus and Mercury’s orbits, but then embarked even to beyond Neptune’s orbit. When the Comet is far away from the Sun, it’s nothing more than an ordinary ball of frozen gas and dust that poorly reflects the sunlight. But, when it comes closer to the Sun, the gas is heating and becoming fluorescent. So the gas and the dust are partially scattered, illuminated by sunlight, creating the characteristic fog tail.
The Halley’s Comet needs 76 years period to cross its entire orbit, and during all that time it is close to the Sun very shortly, only once and that is the time when we can see it. Many artificial satellites were made to follow the Halley’s Comet, one of them, Giotto, was launched in July 1985 and met the Comet in March 1986 – part of VEGA expedition. It is presented on the walls with Epiphany in the chapel of Revelation in Padova. Its characteristic shape presented in the painting makes us believe that the artist who made it actually saw the Halley’s Comet in 1301, between September and October when she was visible in 6-weeks period. It got the name after the astronomer who discovered it – Edmund Halley. There are many sayings emerged from the Halley’s Comet appearance time, like this one: Most beautiful things in our lives are often like the Halley Comet. No matter how much we want to see them, they come along rarely and even then we’re too busy to notice them. And many others that want to say that something happenes very rarely, almost never. The next occurance of this Comet is expected in 2061.