leosin / ephemeris

Javascript implementation of Moshier's ephemeris calculations for sun, planets, comets, asteroids and stars.

This source is modified version of xerik. Thank you for such a brilliant piece of work.

This is basically JavaScript implementation of Moshier's ephemeris calculations for sun, planets, comets, asteroids and stars.

Which, initially written by mivion, xerik converted it into a node module. This is a slight customized version with following changes:

1. Changes the transit method to get standard sun/moon rise/set times as well as a custom horizon based
2. Takes in JavaScript date object as opposed to a date time string
3. Implements a method to just fetch in single planet as opposed to all of it
4. Removes html, css bit to keep it focused to one task
5. Reformats the code

Installation

npm install ephemeris

Changelog

2.0.0 Breaking Changes - Please read carefully

• Released 5th July 2020
• Removes dependency on Moment.js and uses JavaScript's default date object
• Fixes names of a few variables as there were typos (Thanks Erik for these changes)

1.0.0

• Released 30th June 2020
• updates test and fixes test

Usage

app.js

const ephemeris = require('ephemeris');
const dateObj = new Date('2015-08-10T17:09:01.000+08:00');

// parameters: ephemeris.getAllPlanets(dateObj, longitude, latitude, height);
var result = ephemeris.getAllPlanets(dateObj, 10.0014, 53.5653, 0);

/* Check out the namespaces: date, observer and observed:

{ date:
   { gregorianTerrestrial: '10.8.2015 17:9:1',
     gregorianTerrestrialRaw:
      { day: 10,
        month: 8,
        year: 2015,
        hours: 17,
        minutes: 9,
        seconds: 1,
        julianDate: 2457244.5,
        julianTime: 0.7145949074074074,
        julian: 2457245.2145949076,
        j2000: 2015.6063370154895,
        b1950: 2015.6065478300004,
        j1900: 2015.6063370154895,
        delta: 68.01714323102905,
        terrestrial: 2457245.2145949076,
        universal: 2457245.2138076723,
        universalDate: [Object],
        universalDateString: '10.8.2015 17:7:52.983' },
     gregorianUniversal: '10.8.2015 17:7:52.983',
     gregorianDelta: '00:00:68.01714323102905',
     julianTerrestrial: 2457245.2145949076,
     julianUniversal: 2457245.2138076723,
     julianDelta: 0.0007872354540628362 },
  observer:
   { name: 'earth',
     longitudeGeodetic: 10.0014,
     longitudeGeocentric: 10.0014,
     latitudeGeodetic: 53.5653,
     latitudeGeocentric: 53.38123133267187,
     heightGeodetic: 0,
     heightGeocentric: 6364.336264644461 },
  observed:
   { sun:
      { name: 'sun',
        raw: [Object],
        apparentLongitudeDms30: '17°45\'39"',
        apparentLongitudeDms360: '137°45\'39"',
        apparentLongitudeDd: 137.76105855382917,
        geocentricDistanceKm: -1 },
     mercury:
      { name: 'mercury',
        raw: [Object],
        apparentLongitudeDms30: '5°2\'10"',
        apparentLongitudeDms360: '155°2\'10"',
        apparentLongitudeDd: 155.03637003916958,
        geocentricDistanceKm: -1 },
     venus:
      { name: 'venus',
        raw: [Object],
        apparentLongitudeDms30: '25°43\'16"',
        apparentLongitudeDms360: '145°43\'16"',
        apparentLongitudeDd: 145.7212923824036,
        geocentricDistanceKm: -1 },
     moon:
      { name: 'moon',
        raw: [Object],
        apparentLongitudeDms30: '2°41\'17"',
        apparentLongitudeDms360: '92°41\'17"',
        apparentLongitudeDd: 92.68823373136327,
        geocentricDistanceKm: 61.007764233212335 },
     mars:
      { name: 'mars',
        raw: [Object],
        apparentLongitudeDms30: '1°7\'20"',
        apparentLongitudeDms360: '121°7\'20"',
        apparentLongitudeDd: 121.12222806696656,
        geocentricDistanceKm: -1 },
     jupiter:
      { name: 'jupiter',
        raw: [Object],
        apparentLongitudeDms30: '29°50\'16"',
        apparentLongitudeDms360: '149°50\'16"',
        apparentLongitudeDd: 149.83799891400335,
        geocentricDistanceKm: -1 },
     saturn:
      { name: 'saturn',
        raw: [Object],
        apparentLongitudeDms30: '28°20\'25"',
        apparentLongitudeDms360: '238°20\'25"',
        apparentLongitudeDd: 238.34045318452542,
        geocentricDistanceKm: -1 },
     uranus:
      { name: 'uranus',
        raw: [Object],
        apparentLongitudeDms30: '20°24\'33"',
        apparentLongitudeDms360: '20°24\'33"',
        apparentLongitudeDd: 20.40921989582207,
        geocentricDistanceKm: -1 },
     neptune:
      { name: 'neptune',
        raw: [Object],
        apparentLongitudeDms30: '8°58\'37"',
        apparentLongitudeDms360: '338°58\'37"',
        apparentLongitudeDd: 338.9771304673532,
        geocentricDistanceKm: -1 },
     pluto:
      { name: 'pluto',
        raw: [Object],
        apparentLongitudeDms30: '13°27\'13"',
        apparentLongitudeDms360: '283°27\'13"',
        apparentLongitudeDd: 283.4537823191463,
        geocentricDistanceKm: -1 },
     chiron:
      { name: 'chiron',
        raw: [Object],
        apparentLongitudeDms30: '20°41\'58"',
        apparentLongitudeDms360: '350°41\'58"',
        apparentLongitudeDd: 350.6995558283406,
        geocentricDistanceKm: -1 },
     sirius:
      { name: 'sirius',
        raw: [Object],
        apparentLongitudeDms30: '11°27\'17"',
        apparentLongitudeDms360: '101°27\'17"',
        apparentLongitudeDd: 1.7707222368344282,
        geocentricDistanceKm: 7777 } } }
*/

Contributors

This implementation based on code by Steve Moshier.

The initial JavaScript code has been written by xerik.

License

GPLv3