thunkii.bsky.social

thunkii.bsky.social

@thunkii.bsky.social

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thunkii.bsky.social reposted

Last year I rewrote Wikipedia's article on Makemake and it's now featured on the front page!! i spent 2 months hyperfixating on this topic and doing all the research and writing. It was SO worth it :D Special thanks to @renerpho.bsky.social & others for reviewing it ^^ (1/12 thread) 🔭 #planetsci

A thread of explanatory notes is in my thread from then: bsky.app/profile/thun...

thunkii.bsky.social@thunkii.bsky.social

Other categories of asteroids are harder to spot. The 'Hildas triangle' in purple results from a 3:2 orbital resonance keeping them away from Jupiter. Near-Earth asteroids in red and yellow tend to be much smaller but can pose a threat to Earth, as do various short-period comets (green).

There are more ways to visualize asteroids, such as their location in space today. Here are 1,509,413 of them, plotted to scale with each other (but not to the planets or their orbits). We can clearly see the main belt in white and Trojan asteroids in pink.

View full thread

Positions, sizes, and magnitudes of asteroids are derived from the JPL Small Bodies Database, with orbital elements integrated from the provided epoch (mostly November 2025). Planet positions are from DE440; coordinates are in the J2000 ecliptic, with the +x axis pointing to the vernal equinox.

There are more ways to visualize asteroids, such as their location in space today. Here are 1,509,413 of them, plotted to scale with each other (but not to the planets or their orbits). We can clearly see the main belt in white and Trojan asteroids in pink.

View full thread

The side view of the asteroid belt (bottom) shows that it's more of a donut, though it is far emptier--space is big, and most asteroids are found several million km from each other. The pink Trojans can have high-inclination orbits, due to the stability of Jupiter's L4 and L5 Lagrange points.

We can also see that the plane of the main belt is tilted slightly away from Earth's orbit and closer to the Solar System's invariable plane. The same is true of the classical Kuiper belt. The biggest yellow dot between Earth and Mars's orbit is 433 Eros, visited by NEAR Shoemaker in 2001.

There are more ways to visualize asteroids, such as their location in space today. Here are 1,509,413 of them, plotted to scale with each other (but not to the planets or their orbits). We can clearly see the main belt in white and Trojan asteroids in pink.

Other categories of asteroids are harder to spot. The 'Hildas triangle' in purple results from a 3:2 orbital resonance keeping them away from Jupiter. Near-Earth asteroids in red and yellow tend to be much smaller but can pose a threat to Earth, as do various short-period comets (green).

thunkii.bsky.social reposted

🧵 Link to high-resolution versions of inclination and eccentricity vs. semi-major axis at end of thread Proper elements from David Nesvorný's catalog www2.boulder.swri.edu/~davidn/Prop... David's paper: iopscience.iop.org/article/10.3...

iopscience.iop.orgA Census before Rubin of Asteroid Families in the Main BeltA Census before Rubin of Asteroid Families in the Main Belt, Nesvorný, David
thunkii.bsky.social@thunkii.bsky.social

This is a graph of the inclination vs semi-major axis (distance from the sun) of 1,249,051 asteroids in the asteroid belt. Using proper elements allows us to see the belt's fine structure, including asteroid families that are fragments of past collisions. Each asteroid is (roughly) to scale.

This is a graph of the inclination vs semi-major axis (distance from the sun) of 1,249,051 asteroids in the asteroid belt. Using proper elements allows us to see the belt's fine structure, including asteroid families that are fragments of past collisions. Each asteroid is (roughly) to scale.

View full thread

This is a graph of the inclination vs semi-major axis (distance from the sun) of 1,249,051 asteroids in the asteroid belt. Using proper elements allows us to see the belt's fine structure, including asteroid families that are fragments of past collisions. Each asteroid is (roughly) to scale.

Here's another graph, showing the eccentricity vs the semi-major axis. While most asteroids are ejected from the major resonances with Jupiter, forming the Kirkwood gaps, some are trapped there and gradually excited onto planet-crossing orbits.

Asteroids range in size from the four largest: Vesta (inner belt), Ceres and Pallas (mid belt), and Hygiea (outer belt), to millions of kilometer-size rocks that are barely one pixel across. If you look closely at top left of the inclination plot, you can see the small but bright Hungarias (orange).

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