vmm-stargazing

Night sky along the VMM 100 — look up from the Hoàng Liên Sơn, make a memory, think bigger.

Pre-computed notes for Vietnam Mountain Marathon 100 Miles 2026 (Sa Pa): planets, moon, constellations, and DSM ridge vs stars at the best stargazing places on the course. Not a live planetarium.

Notes: GitHub Pages

Waypoints: stargazing-spots.gpx — also a download on the site.

Quick start

make install
make test
make run

make run writes the public site into docs/. First run downloads Copernicus GLO-30 and the de421 ephemeris into ~/Documents/data/vmm-stargazing (DATA_DIR / DATA_ROOT override).

See usage.md for knobs and architecture.md for how the stages connect. Where this is going: ROADMAP.md.

Race

• Distance: ~161 km, ~8800 m elevation gain.
• Start: Friday 18 September 2026, 08:00 local (Asia/Ho_Chi_Minh, UTC+7) at Sapa Square.
• Finish cutoff: Sunday 20 September 2026 ~09:00 (49 h). Predicted finishes are earlier (optimistic / realistic / conservative).
• Location: Sa Pa / Hoàng Liên Sơn, ~22.34° N, 103.84° E.

Race start, GPX path, and predicted-pace knobs live in config.yaml. The course GPX lives in gpx/. DEM caches and ephemeris stay out of git.

Along-track time uses the realistic predicted pace (when you reach a place). Which places are good for looking up is the best sample in each stretch of night (heading-open DSM sky, elevation on that night, moon, Milky Way centre) — not aid-station cutoffs.

New course GPX

1. Put the file in gpx/ and set gpx: in config.yaml to that path, or pass it once: make run GPX=/path/to/course.gpx.
2. Point config.yaml at the new event: race.name, race.location, start_time, cutoff_time, timezone. Replace checkpoints.csv if the course has published cutoffs.
3. If the track is in a new area: make clean-dem.
4. make run. First time on a new bbox downloads GLO-30; de421 is reused if already in $DATA_DIR. The site in docs/ is generated from that run — do not edit the HTML by hand.
5. Commit docs/ (including stargazing-spots.gpx) to update GitHub Pages.

pace: stays in config.yaml unless you have a new model. Knobs: usage.md.