TIL about Kirkwood gaps. I knew about Jupiter leading to Hilda and Trojan groupings, but my understanding of the main belt was more in line with a representation like this one from Wikipedia[1]. However, this imaging shows a clear gap and a quick search led me to learn about Kirkwood gaps. Is there a specific reason why the gap is more evident in this imaging rather than the above one from Wikipedia?
[1] - https://en.wikipedia.org/wiki/File:InnerSolarSystem-en.png
You should not be able to see the Kirkwood gaps if the simulation is accurate; the Wikipedia image is more realistic.
The "gap" only applies to the semi-major axis (which is proportional to the 3/2th power of the period); since most asteroids are somewhat eccentric (and since semi-major axis is relative to the center but orbits are based on a focus, which "moves" rapidly as the circle deforms) there are always asteroids crossing the "gap" between perihelion (far short of the semi-minor axis, even) and aphelion (far beyond the semi-major axis).
I'm too lazy to do the math, but based on planets with similar eccentricity, most asteroids are between 10% and 25% farther at aphelion than at perihelion (or, often between 0.25AU and 0.75AU farther), which easily crosses any single gap, and almost always multiple gaps.
See the images at https://en.wikipedia.org/wiki/Orbital_eccentricity for informative images of ellipses.
I suspect the gap is at least 50% rendering artifact, but all 1.4M asteroids are plotted as (small) fraction of its orbital ellipse, so the density distribution is reflective of the real data (more specifically, orbit types)
If I understand both the code and o11c's comment correctly, it sounds like the difference is less rendering artifact rather than what is being rendered. This code is rendering the asteroids based off their semi-major axis, but Wikipedia appears to be rendering their actual positions at a specific moment in time with the asteroids all at various points in their eccentric orbit.
I am pretty sure it is the opposite :)
Care to expand on that? Wikipedia image has the Greeks ahead of Jupiter and the Trojans behind Jupiter. Doesn't that clearly show it is an image of a moment in time? And the only attributes of an asteroid this code[1] seems to use are the eccentricity, semi-major axis, and perihelion. Although I'm no expert in either Python or astrophysics so I may be missing something.
[1] - https://github.com/DarkStar1982/Orbidium/blob/536afc2e12e9a2...
The code draws full orbit ellipse if selected to do so, but the original picture was rendered using a different mode, where just a small slice of the orbit arc is rendered, pretty much showing an instantaneous position of asteroid.
Now, I am pretty sure actual positions are not correct relative to each other (it is the same position on ellipse arc, should be actual position of the asteroid) but MPC file doesn't provide this information - you need ephemeris from here: https://www.minorplanetcenter.net/iau/MPEph/MPEph.html
After all, it is mostly a data visualization demo (although I tried to be precise with scale too)
Demo written by the team from Exodus Orbitals.
We have a few more cool projects in the pipeline - sign up to learn about them here
https://exodusorbitals.us4.list-manage.com/subscribe?u=959a0...
Is the lack of asteroids between the Earth and Sun an artifact of our methods of detection? I'd imagine looking outward where light is shining on a surface would be easier to detect stuff than looking inward towards the sun at such a close distance.
Not entirely, but in part! You can see the effect in this animation of asteroid discoveries over time, where the discoveries are concentrated in bursts facing directly away from Earth, or directly parallel to its orbit.
There are not that many, less than a 100 with apoapsis inside of the Earth orbit.
Rendering can be adjusted for better visibility, but 4 inner planets swept the interior volume pretty thoroughly during earlier times of Solar System.
older video but doesn't require downloading and compiling https://www.youtube.com/watch?v=vfvo-Ujb_qk Also if you are worried, here is a good video talking about it https://www.youtube.com/shorts/gBzDC6yMw9Y?feature=share
First step to mining a NEO is knowing where they are.
