(a thread on asteroid (3200) Phaethon, why I like it, and how and why we can study things that look like dead comets)
![](https://pbs.twimg.com/media/De8j5BjV4AIAzYF.jpg)
![](https://pbs.twimg.com/media/De8kbFWVMAAJxzS.jpg)
It was awesome, honestly. There's a really visceral sense of the importance of that mountain when you're on it.
![](https://pbs.twimg.com/media/De8mCvrVAAEh5D6.jpg)
The IRTF's mirror, you know, the actual telescope, is behind me in the image.
![](https://pbs.twimg.com/media/De8oO_uVQAEohHN.jpg)
Asteroids get numbers (e.g. 3200 for Phaethon) when their orbit is sufficiently well known, usually meaning that we've observed it throughout multiple orbits.
The Good: it explains how it created the Geminids, but no longer is able to. It explains (at least qualitatively) the incredibly eccentric orbit that brings it so close to the Sun.
HYPOTHESIS: Phaethon is a main-belt asteroid, perhaps from (2) Pallas, that used to display main-belt-comet-like activity, maybe driven by its orbital migration inwards.
![](https://pbs.twimg.com/media/De843iQVMAA1VVX.jpg)
![](https://pbs.twimg.com/media/De85hiWVQAAYJOl.jpg)