deskephem - Modular CLI Astronomy

$ deskephem moon phase # Werewolf early warning system
🌒 Waxing Crescent (5.0%)
$ deskephem -l 30n,60w -E now,1h,+4h venus horiz  # Table of the location of venus, 1 hour for 4 hours into the future
===================================================
         Date             Coordinates (Azi/Alt)    
===================================================
 2025-03-31T23:50:03  41°54′54.7″ -45°00′-31.5″    
 2025-04-01T00:50:03  56°49′18.1″ -35°00′-59.7″    
 2025-04-01T01:50:03  67°53′57.5″ -23°00′-10.4″    
 2025-04-01T02:50:03  76°46′8.2″ -11°00′-25.5″     
 2025-04-01T03:50:03  84°33′9.8″ +1°20′41.0″       
$ deskephem -d 1781-03-13 -l 53n,1.8w Uranus horiz magnitude # Location and brightness of Uranus at William Herschel's first observation
278°45'42.91" 23°22'1.52" 5.60

deskephem is a CLI astronomy calculator for celestial objects such as the moon, planets, stars, and sun:

• Coordinates in the sky (equatorial, horizontal, ecliptic)
• Phase (Emoji, Illuminated Fraction, Name)
• Approximate Rise and Set times
• Brightness (Magnitude)
• Distance
• Angular Size
• Angles between other objects in the sky

It's catalog contains the moon, sun, planets, and about 100 common stars

It supports outputs in json, csv, and plain text. It can also generate tables of output:

$ time deskephem -l 35n,100w --ephem=-3h,1h,+3h sun horiz -Tcsv
Date,Coordinates (Azi/Alt)
2025-03-31T20:56:28,284°33′21.7″ -12°00′-45.4″
2025-03-31T21:56:28,294°35′42.9″ -24°00′-30.1″
2025-03-31T22:56:28,306°48′56.6″ -34°00′-53.9″
2025-03-31T23:56:28,322°31′54.9″ -43°00′-24.8″
2025-04-01T00:56:28,342°40′49.8″ -49°00′-8.6″
2025-04-01T01:56:28,05°53′2.9″ -50°00′-38.6″
2025-04-01T02:56:28,27°56′2.2″ -46°00′-36.1″
$ time deskephem -E 1600-01-01,1mon,9999-06-01 mars ecliptic # Query is ran ~100k times
===================================================
         Date            Coordinates (Ecliptic)    
===================================================
 1599-12-31T18:09:24  143°04′10.6″ +3°48′36.4″     
 1600-01-31T18:09:24  133°03′30.5″ +4°31′51.0″     
[...]
1.89 user 0.20 system

deskephem is a wrapper around the pracstro astronomy library

Parameters

All input to deskephem is case insensitive

Options:

• Date: -d [DATE] (default: now)
• Observer Latitude/Longitude: -l [LAT,LONG] (default: none)
• Output format: -T [FORMAT] (default: term, options: csv, json, term)
• Ephemeris generation: -E start,step,end (optional)

Arguments:

• Object being observed
• Properties

Properties

Equatorial Coordinates: equ, equa, equatorial Horizon Coordinates: horiz, horizontal Ecliptic Coordinates: ecl, ecliptic Distance: dist, distance (Brightness) Magnitude: mag, magnitude, brightness Phase Info: phase Phase Emoji: phaseemoji Phase Name; phasename Angular Diameter: angdia Illuminated Percent: phaseprecent, illumfrac Rise and set times: rise, set Angle between objects: angbetween:{Object}

Input formatting

Dates:

• Relative Dates: +/-#y/mon/d/h/min/s (ex. +3mon)
• Time increments: #y/mon/d/h/min/s (ex. 1w)
• ISO format: YYYY-MM-DD[THH:MM:SS] (ex. 1970-01-01T14:40:25, 2000-04-52)
• Unix dates: @# (ex. @86400)
• Julian dates: ##j[d] (ex. 2451545)
• Now: now (ex. now)

Angles:

• Lat/Long: Angle,Angle (ex. 0,0, 30n,60w)
• Degrees: ###°/d[eg] (ex. 45deg)

Epehmeris Queries: Date (Start),Time Increment,Date (End)

Object:

• Object name: {name} (ex. moon, Sun, Arcturus)
• Raw coordinates: latlong:{lat,long} (ex. latlong:0,45w)