20 years
Like any orbit, it may change over time.
This is Kepler's Third Law of Planetary Motion. Let's assume the orbit is circular. The law is: The time to orbit the Sun, squared, is proportional to the distance from the Sun, cubed. Really the orbits are ellipses and we need to use the "semi-major axis" of the ellipse instead of simply the distance from the Sun.
The moon is in constant orbit around the earth, all the time.
Jupiter does not orbit the earth. It takes 11.86 years for Jupiter to orbit the sun.
unknown
Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.Planets have years based on the time it takes them to orbit the sun. The sun does not orbit itself, so it does not have a year.
By observing the comet in different times and positions, and figuring out a "best fit" of the orbit.
180
about a many days and years...
neptunes orbit time of the sun is 164.79 years to orbit the sun neptunes orbit time of the sun is 164.79 years to orbit the sun
There is no 'periodic' change in the earths orbit. The orbit is elliptical and over time (a great many years) becomes less so.
once
There are many American past-times, most of which include sports. There are many debates over if baseball or football is the best, but baseball has been called "The Great American Past-Time" for many years.
20 years
you need to have the eye of truth
Like any orbit, it may change over time.