# Didymos

*In the Solar System*

A near-Earth asteroid with a small moon, Dimorphos, and the target of the only deliberate attempt to move one: DART hit the moon in September 2022 and shortened its orbit around Didymos by 32 minutes, far more than the change anybody had predicted. It is here for that. ESA's Hera arrives at the end of 2026 to measure what a strike of a known energy actually did, which is the number the experiment was for.

| | |
| --- | --- |
| Radius | 0 km |
| Around the equator | 2 km |
| From the Sun | 227,901,052 km (-815,167 km/d) |
| From the Earth | 181,292,047 km (+608,672 km/d) |
| A signal takes | 10 min |

Distances and speed are computed from JPL Horizons trajectories and are true of 2026-09-05, changing at the rate given beside each. The interpolation itself is good to a few kilometres; what ages these figures is the date, not the arithmetic.

## Elsewhere

- On the live map: https://www.orbitalmap.space/?world=solar-system&focus=didymos
- This object as a page: https://www.orbitalmap.space/o/didymos/
- Every object: https://www.orbitalmap.space/o/
- What this site is and what it reads: https://www.orbitalmap.space/llms.txt