# How many degrees / radians is one full orbit of the Earth?

• I
• Patrick Aberdeen
In summary, the Earth's orbit around the sun consists of slightly more than 360° of rotation on its axis, due to its orbit around the Milky Way. The plane of the Earth's orbit is inclined to the plane of the Sun's orbit around the Milky Way, but the difference in degrees is much smaller than 90. The Sun and the rest of the Solar System have a complex orbit around the Milky Way, which includes both a circular orbit around the center and an oscillation above and below the spiral arms and disk. This oscillation has a period of approximately 30 million years, while the entire orbit around the Milky Way takes about 220 million years. Therefore, the difference between a sidereal year and a Milky Way year

#### Patrick Aberdeen

One day consists of slightly more than 360° of rotation (360.9856°) on it's axis (due to Earth's orbit around the Sun).

I imagine that one orbit is also either > or < 360° around the sun, relative to the motion of the sun around some object. Is this true, or is the orbit of the Earth perpendicular to the motion of our solar system relative to other celestial objects (solar systems, galaxies etc.)?

The Sun, along with the rest of the Solar System, orbits the Milky Way in a somewhat complicated orbit: more or less circular around the center, with a period ~ 220 MYr. But it also oscillates above and below the MW's spiral arms and disk with a period ~ 30 MYr. (FWIW, we are headed in the direction of the constellation Hercules at this point in the Sun's orbit.)

The plane of the Earth's orbit is somewhat inclined to the plane of the Sun's orbit around the MW, but much less than 90 degrees.

It does not make sense to talk about periodic orbits for other objects that include the Sun. It is true that the MW and Andromeda Galaxy are interacting gravitationally, but that is not at all a periodic orbit. They will have a more-or-less head-on collision in several GYr. (So there are no radians involved in that.)

JMz said:
The Sun, along with the rest of the Solar System, orbits the Milky Way in a somewhat complicated orbit: more or less circular around the center, with a period ~ 220 MYr. But it also oscillates above and below the MW's spiral arms and disk with a period ~ 30 MYr. (FWIW, we are headed in the direction of the constellation Hercules at this point in the Sun's orbit.)

The plane of the Earth's orbit is somewhat inclined to the plane of the Sun's orbit around the MW, but much less than 90 degrees.

It does not make sense to talk about periodic orbits for other objects that include the Sun. It is true that the MW and Andromeda Galaxy are interacting gravitationally, but that is not at all a periodic orbit. They will have a more-or-less head-on collision in several GYr. (So there are no radians involved in that.)

Thank you! That gives me a big head-start on learning more about our solar system's motion. I'm guessing from your answer that the Earth's orbit around the sun is therefore very very slightly more or less than 360°, due to its incline to the plane of the Sun's orbit around the MW. Compared to the difference between a sidereal day and a solar day (56 minutes), I'm getting from your answer that the difference would be between a sidereal year and a MW year. Is that right? And that this difference would be so trivially tiny (given the 220 MYr period) that practically speaking we can leave it at 360°? Thanks again for for the explanation!

Patrick Aberdeen said:
Thank you! That gives me a big head-start on learning more about our solar system's motion. I'm guessing from your answer that the Earth's orbit around the sun is therefore very very slightly more or less than 360°, due to its incline to the plane of the Sun's orbit around the MW. Compared to the difference between a sidereal day and a solar day (56 minutes), I'm getting from your answer that the difference would be between a sidereal year and a MW year. Is that right? And that this difference would be so trivially tiny (given the 220 MYr period) that practically speaking we can leave it at 360°? Thanks again for for the explanation!
That's exactly right. (Sometimes called a "galactic year", BTW -- though of course it's the Solar System that has the orbit, not the Galaxy.)

Thank you so much. It was driving me nuts not being able to find the answer for that one :)

OK. I imagine it's not an FAQ for very many sources. :-)

Patrick Aberdeen said:
Thank you! That gives me a big head-start on learning more about our solar system's motion. I'm guessing from your answer that the Earth's orbit around the sun is therefore very very slightly more or less than 360°, due to its incline to the plane of the Sun's orbit around the MW. Compared to the difference between a sidereal day and a solar day (56 minutes), I'm getting from your answer that the difference would be between a sidereal year and a MW year. Is that right? And that this difference would be so trivially tiny (given the 220 MYr period) that practically speaking we can leave it at 360°? Thanks again for for the explanation!

For what it's worth, the difference between a solar day and a sidereal day is only 4 minutes, not 56 minutes.

russ_watters
phyzguy said:
For what it's worth, the difference between a solar day and a sidereal day is only 4 minutes, not 56 minutes.
Right: Length is 23 hours and 56 minutes.

## 1. How many degrees is one full orbit of the Earth?

One full orbit of the Earth is equivalent to 360 degrees.

## 2. How many radians is one full orbit of the Earth?

One full orbit of the Earth is equivalent to 2π radians.

## 3. Why is one full orbit of the Earth measured in degrees and radians?

Degrees and radians are both units of measurement used to quantify angles. While degrees are commonly used in everyday life, radians are often used in scientific calculations due to their mathematical properties. Both units are used to measure one full orbit of the Earth to provide a comprehensive understanding of its rotation.

## 4. How is one full orbit of the Earth calculated in degrees and radians?

One full orbit of the Earth is calculated by dividing the circumference of the Earth's orbit by its radius. This calculation results in the angle measurement in both degrees and radians.

## 5. Does the Earth's orbit change in degrees and radians over time?

No, the Earth's orbit remains constant in both degrees and radians over time. However, it is important to note that the Earth's orbit is not a perfect circle and does experience slight variations due to gravitational forces from other celestial bodies.