---
name: close-approach-watch
description: >
  This skill should be used when the user asks "which asteroids are passing Earth this month",
  "any close approaches this week", "is any asteroid going to hit us", "near-Earth objects coming up",
  "asteroid flyby for our assembly/newsletter", or wants upcoming close approaches explained in plain English.
metadata:
  version: "0.4.0"
---

# Close-approach watch

Report upcoming asteroid and comet flybys calmly and accurately, with sizes and distances people can picture.

## Client compatibility

Use the connected PublicUniverse MCP server (`publicuniverse`); clients may prefix or namespace its tool names. Match the tools below to the names and argument schemas actually exposed by the client. If the connection or a required tool is unavailable, explain what cannot be checked and ask the user to connect it; do not invent live results. Read references relative to this skill's directory. If browsing or file creation is unavailable, state that limit and provide the supported part of the result.

## Steps
1. **Window and threshold.** Default to the next 30 days, with Earth as the body and `max_dist_au=0.05` (about 19.5 lunar distances). Narrow to 0.01 AU for "really close" lists.
2. **Query** `find_close_approaches(date_min, date_max, body="Earth", max_dist_au, limit)` from the PublicUniverse MCP (`publicuniverse`). For interesting objects, follow up with `get_object`, which includes orbit quality (`condition_code`), `pha` status and observation arc.
3. **Size.** Use `radius_km` if present. Otherwise estimate the diameter from `absolute_magnitude_h` using the method in `references/data-caveats.md` and give a range (e.g. "roughly 6–15 m, about the size of a bus").
4. **Distance.** Convert AU to km (1 AU = 149,597,871 km) and to **lunar distances** (LD = 384,400 km). Treat `dist_min_au` as an uncertainty estimate, not a guaranteed minimum distance.
5. **Speed.** `v_rel_km_s`, with an everyday comparison (e.g. "about 30 times faster than a rifle bullet"). Show the arithmetic.

## Framing
- Describe the predicted flyby distances calmly. Do not infer an impact probability or guarantee safety from a close-approach listing. PublicUniverse lists close approaches, not impact risk assessments. For risk, point to ESA NEOCC or NASA CNEOS Sentry.
- Small objects can still cause damaging airbursts; do not call them harmless based on size alone. Explain "potentially hazardous asteroid" as a classification by size and orbit, not a prediction.
- Note that orbits with a high `condition_code` (uncertain orbits) can shift as more observations arrive.

## Output
A short intro, then a table sorted by date:

| Date (local) | Object | Est. size | Closest distance | Speed | Link |

Links go to `https://publicuniverse.net/objects/<id>`. For assemblies or newsletters, add a 3-sentence kid-friendly summary on request.