# How close will comet come to earth

• scatterbrain8
In summary, the distance between a comet and Earth can vary widely and the time of closest approach can also vary. While comets can come relatively close to Earth, the likelihood of a collision is very low. Whether a comet is visible to the naked eye depends on its size and brightness, and their frequency of passing by Earth varies depending on their size and trajectory. It is best to research specific comets for accurate information on their closest approach and visibility.
scatterbrain8
I'm given the six orbital parameters for a comet and am asked to find how close it comes to earth, but I'm not sure how to go about this...

Should I calculate the position of the comet and Earth and the comet's perihelion passage? If so, are there equations for this type of thing?

The parameters are a=110 AU, e=0.995, i=89 deg, longitude of the ascending node is 180 deg, argument of perihelion= 0 deg and time of perihelion passage = 2008 March 21

I know it's vernal equinox, but not sure how to quantify the positions...

Last edited:
figured it out, nevermind

I would approach this question by first understanding the orbital parameters and their significance. The parameter "a" represents the semi-major axis, which is the average distance between the comet and the sun. "e" represents the eccentricity, which describes the shape of the comet's orbit (a perfect circle has an eccentricity of 0, while a highly elliptical orbit has an eccentricity close to 1). "i" represents the inclination, which is the angle between the comet's orbital plane and the plane of Earth's orbit. The longitude of the ascending node and argument of perihelion describe the orientation of the comet's orbit in space. Finally, the time of perihelion passage is the moment when the comet is closest to the sun.

To determine how close the comet will come to Earth, we need to calculate the distance between the comet and Earth at the time of perihelion passage. This can be done using Kepler's laws of planetary motion and the orbital parameters given. Specifically, we can use the equation for the distance of a body from the focus of its elliptical orbit:

r = a(1-e^2)/(1+e*cos(θ))

Where r is the distance between the comet and the sun, a is the semi-major axis, e is the eccentricity, and θ is the true anomaly (the angular distance of the comet from the perihelion point). We can then use this equation to calculate the distance between the comet and Earth at the time of perihelion passage.

Additionally, we can use the time of perihelion passage and the orbital period of the comet to determine the position of the comet and Earth at that time. This can be done using the equation for Kepler's third law:

T^2 = (4π^2/GM)a^3

Where T is the orbital period, G is the gravitational constant, M is the mass of the sun, and a is the semi-major axis. By plugging in the values for the orbital period and semi-major axis given, we can solve for the time of perihelion passage. We can then use this information to calculate the positions of the comet and Earth at that time.

In summary, to determine how close the comet will come to Earth, we need to use the given orbital parameters and equations for Kepler's laws of planetary motion. We can calculate the distance between the comet and Earth at the time

## 1. How close will the comet come to Earth?

The distance between a comet and Earth can vary widely depending on the comet's trajectory and size. Some comets may come as close as a few million miles from Earth, while others may pass by at a much greater distance.

## 2. When will the comet be closest to Earth?

The time of closest approach for a comet can also vary. Some comets may pass by Earth quickly, while others may take weeks or months to make their closest approach. It is important to check with reliable sources for the most accurate information on when a specific comet will be closest to Earth.

## 3. Is the comet a threat to Earth?

While comets can come relatively close to Earth, the likelihood of a comet actually colliding with our planet is very low. The size and trajectory of most comets make it unlikely for them to pose a threat to Earth.

## 4. Can I see the comet with the naked eye?

Whether or not a comet is visible to the naked eye depends on its size and brightness. Some comets may be bright enough to see without a telescope, while others may require specialized equipment to view. It is best to research specific comets to determine if they will be visible to the naked eye.

## 5. How often do comets come close to Earth?

Comets can come close to Earth at varying intervals. Some comets may only pass by once in hundreds or thousands of years, while others may have shorter orbits and pass by more frequently. The frequency of comets passing by Earth also depends on their size and trajectory.

• Introductory Physics Homework Help
Replies
4
Views
2K
Replies
1
Views
3K
• Introductory Physics Homework Help
Replies
2
Views
1K
• Astronomy and Astrophysics
Replies
3
Views
3K
• Astronomy and Astrophysics
Replies
10
Views
4K
• Astronomy and Astrophysics
Replies
4
Views
4K
• Astronomy and Astrophysics
Replies
1
Views
3K
• Astronomy and Astrophysics
Replies
45
Views
81K
• Sci-Fi Writing and World Building
Replies
22
Views
8K
• Astronomy and Astrophysics
Replies
6
Views
3K