Space Science with Python #14: Asteroid Flyby
In my last article I wrote about close asteroids, or: objects that have a close encounter or flyby with our home planet. Sometimes, you may hear it in the news that some objects pass the Earth in different close proximities. Last year, 2022, there were several occurrences. One was the Near-Earth Object 2021 WP.
2012 WP crossed the Earth’s so called Sphere of Influence (SOI). The SOI is an imaginary sphere that allows one to simplify complex astro-dynamical problems: To determine the gravitational influence of celestial objects on other objects, like asteroids, one needs to consider all gravitational “sources”: The Sun, the Earth, other smaller objects, the planets, and so on. Complex N-body simulations provide a detailed computational understanding on changing trajectories and orbits of objects; but they are computational heavy and expensive.
However, the SOI is a concept that allows one to create simple 2-Body problems. For example, within Earth’s SOI we can ignore the Sun, Jupiter and other objects and determine the trajectory of e.g., an entering asteroid by considering the Earth as the only gravitational pull.
And that’s what we do here: we use this simple SOI concept to check the gravitational perturbation effects of the Earth on asteroids (before they leave the SOI).
The code can be found here …
… and the corresponding video provides some explanation:
Until next time,
Thomas
