Cosmos

The night sky, offline, wired to your observing notes.

Cosmos draws 8,920 stars, every star down to magnitude 6.5. It adds 3,137 clusters, nebulae and galaxies, all 88 constellations, and the Sun, Moon and planets at their computed positions. The catalogue is about 700 KB on disk. Nothing is fetched at runtime.

Every object carries a stable key: HIP 32349 for a star, NGC 224 for a deep-sky object, with M31 and the common name as aliases. That key lets Cosmos find your notes about an object, whatever spelling you used.

The cartridge id is @mnemosyne-plugins/mnemo-cosmos. Its code lives at Mnemosyne-OS/MnemoCosmos.

Find an object

• Type in Search a name, HIP, NGC or M number.
• Or click an object in the sky. Its card shows the magnitude, distance, spectral type, constellation and position.
• Centre on it turns the sky to the object.

A star with no measured distance shows a dash, never a number.

Time and place

Instant shown sets the moment, in UTC or Local. Now, −1 hour, +1 hour, −1 day and +1 day move it.

Where you are takes a Name, Latitude, Longitude and Elevation (m). Press Use this place. You type the place yourself: Cosmos never looks your location up. Without a place, the card shows no altitude, rise or set time.

The Moon's card shows its phase and how much of it is lit.

The sky's layers

Turn on or off Constellation figures, Constellation names, Deep sky, Sun, Moon and planets, Star names and Coordinate grid. Faintest star shown sets the magnitude limit. Reset the view brings back the start.

Everything sits on one celestial sphere. Cosmos shows directions, not distances.

Ask your memory

Open an object's card and press Ask what my notes say. The question carries the name, the key and the aliases. If your memory holds nothing about the object, Cosmos says so. Each question is a model call, so nothing is asked until you press the button.

Review

Review what you know asks you to name a marked object. Pick a family: Everything, Messier objects, Named stars, Bright stars, Galaxies, Clusters or Nebulae. Then pick the number of questions, or Endless. Missed objects come back the next day. The others move to a longer interval.

Hand gestures

With hand tracking on, Cosmos takes pan, depth, zoom, recenter and select.

Where your data goes

• The catalogue ships with the cartridge and is read from your disk.
• Your review progress and your place are kept by Mnemosyne OS as the cartridge's saved state.
• Save this run to memory writes a review run into Cosmos's own vault.

Data sources and licences, as listed in the cartridge:

• Stars: HYG 4.1, CC BY-SA 4.0.
• Deep sky: OpenNGC, CC BY-SA 4.0.
• Constellation figures and names: d3-celestial, BSD 3-Clause.
• Sun, Moon and planet positions: astronomy-engine, MIT.

The cartridge code is under the MIT licence. The catalogue file built from HYG and OpenNGC is under CC BY-SA 4.0.

For agents

Action	Effect	What it does
status	read	The instant, the place, the view, the layers, the open card.
search	read	Finds stars, deep-sky objects and planets.
goTo	write	Opens an object's card and turns the sky to it.
setTime	write	Another instant, or a shift in hours.
setPlace	write	The place the sky is seen from.
setLayers	write	Layers and the faintest star.
setView	write	Zoom, field, centre, reset.
showConstellation	write	Turns the sky to a constellation.
showPanel, closePanel	write	Search, place, credits or review.

Voice examples: "show Jupiter", "go to the Orion Nebula", "move forward one hour", "hide the star names", "quiz me on the sky".