All comets (there are over 3,500 known) have different time-scales for their appearances.
These depend on the length of their orbits - some comets have extremely large orbits which take them from being 'close' to the earth to almost going out of our solar system.
They appear because they come close enough to the Earth to be seen, and then they may take anything from a few years to hundreds of thousands of years beore they come back.
The best-known comet is Halley's Comet which has a period of between 75 and 76 years between appearances.
Because comets have very elliptical orbits. They go way out in space and move very slowly the further out they go. When they come whipping around the sun they are going fast but then they are heading nearly straight out in space again. As they go out the sun's gravity keeps slowing them down trying to pull them back till they finally stop (the other end of the ellipse) and they fall back toward the Sun but they are so far out the suns gravity is week and they pick up speed slowly till they get close to the sun again and greatly speed up.
Its when they are near the sun that we can see them because they are close. When they are way out even telescopes can't see them.
I assume you mean comets.
Only a few come every 75 years, some come as often as every few years and some not for centuries.
It all depends on their orbit around the sun; the further out they go, the longer it takes them to return.
Comets reappear because they are in fixed orbits; once the orbital parameters are determined, it's relatively easy to calculate when any particular comet should be visible again.
Some comets are "hyperbolic"; they come into the solar system from outside, make a single pass by the Sun, and exit the system completely. And some comets either collide with a planet (as the Shoemaker-Levy 9 comet did when it broke apart and then crashed into Jupiter) or disintegrate and evaporate completely, leaving nothing but a meteor shower in its wake.
And some comets are in such long-period orbits that no one was around the see them the last time, and will not come again for millennia.
probably because all comets return i have posted a question myself and there is only one comet i dont now if is coming back but comet halley will always return unless we are lucly and it never comes back
They all appear when they get close enough to the Sun for us to see them illuminated by the Sun.
Some comets are periodic (they return on a regular basis) and their period of return is governed by their individual, specific orbit round the Sun. There are "short" and "long" period comets.
There are also single-apparition or non-periodic which come in from the Oort cloud on a random basis.
Comets travel in orbits like the planets around the sun. Comets "return" because they are reappearing at a certain point on their orbits which coincides with the earth's orbit.
How often a comet reappears depends on its orbital period. Comets can be either short-period or long-period, with the orbital periods ranging from a few years to millions of years.
because, just like earth they orbit the sun
Gravity.
Gravitational pull
Are you serious?
They come from the outer reaches of space.
Collisions between objects in the Kuiper Belt produce fragments that become comets. The comets are known as short-period comets. Short-period comets take less than 200 years to orbit the sun. Therefore, they return to the inner solar system quite frequently, perhaps every few decades or centuries. Short-period comets also have short life spans. Every time a comet passes the sun, it may lose a later as much as 1m thick.
No, many thousands - probably MILLIONS - of people had observed what we now call "Halley's Comet" in the thousands of years before Edmund Halley realized that this was probably ONE comet coming back MANY times at regular intervals. Halley "predicted" that the comet would return to become visible again, and named the year - and he was right. In his honor, and long after his death, the comet was named for him.
Edmund Halley. He even had a comet named after him, the Halley Comet.
Almost all known comets follow an elliptical or circular path. This means that, over time, they return to our solar system at regular intervals. Astronomers identify each comet, and track its movement while it's in our 'neighbourhood' - then use the data to predict when it will next return.
sir Edmond Halley was the Astronomer/Mathematician who hypothesized that the great comets that had appeared at intervals of 73 to 77 years since ancient times were all the same object, and correctly predicted its return in the late 18th Century. He didn't live to see it return, but when it did, it was named for him.
Gravitational pull
Are you serious?
Comets have been seen and studied by people for thousands of years. Edmond Halley predicted a comet to return in 1705 which is why we call it Halley's Comet or Comet Halley.
They come from the outer reaches of space.
There are scores of comets who's orbits have been determined, and are predicted to return, but the best known one is probably Comet Halley.
A2. There is no maximum orbiting height. Consider for a moment the comets of long return period.
It was 1682. But he didn't know it at the time. The appearance of a large comet in 1682 was an unexpected surprise to everyone, just like all cometary appearances throughout history up to that time. Halley was 26 years old. Late in his life, when he was quite accomplished at orbital calculations in addition to a lot of other things, he noticed historical records of bright comets spaced at regular intervals of between 74 and 77 years, going back centuries before the one in 1682. He proposed that comets were bound to the sun just as the planets are, that they traveled in long eccentric orbits, that the same comets might might be seen repeatedly on several visits to the inner solar system, and that the big one would return in 1758. Halley died in 1742, 16 years before his prediction could be tested. When the big one did in fact return in 1758, it began to be popularly known as Halley's Comet.
Gravity. Specifically, the gravity of the Sun.
He will be a regular until WrestleMania 27. After that, he will return to acting.