{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":1.75,"best_label":"good","best_window":"20:00\u201321:45","dark_hours":9.14,"date":"2027-03-12","moon_free_dark_hours":5.98,"moon_illumination":21,"moon_separation":48.5,"score":null,"score_astronomy":36,"score_weather":null,"transit_alt":42.9,"transit_local":"18:35","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.58,"best_label":"good","best_window":"20:00\u201321:35","dark_hours":9.09,"date":"2027-03-13","moon_free_dark_hours":4.75,"moon_illumination":31,"moon_separation":40.1,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":42.9,"transit_local":"18:35","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.5,"best_label":"good","best_window":"20:00\u201320:30","dark_hours":9.04,"date":"2027-03-14","moon_free_dark_hours":3.57,"moon_illumination":42,"moon_separation":34.4,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":42.9,"transit_local":"18:30","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.08,"best_label":"marginal","best_window":"20:00\u201322:05","dark_hours":8.99,"date":"2027-03-15","moon_free_dark_hours":2.5,"moon_illumination":53,"moon_separation":33.2,"score":null,"score_astronomy":15,"score_weather":null,"transit_alt":42.9,"transit_local":"18:25","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.75,"best_label":"marginal","best_window":"20:05\u201321:50","dark_hours":8.94,"date":"2027-03-16","moon_free_dark_hours":1.58,"moon_illumination":64,"moon_separation":37.0,"score":null,"score_astronomy":11,"score_weather":null,"transit_alt":42.9,"transit_local":"18:20","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.5,"best_label":"marginal","best_window":"20:05\u201321:35","dark_hours":8.89,"date":"2027-03-17","moon_free_dark_hours":0.83,"moon_illumination":75,"moon_separation":44.7,"score":null,"score_astronomy":9,"score_weather":null,"transit_alt":42.9,"transit_local":"18:20","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.42,"best_label":"marginal","best_window":"20:05\u201321:30","dark_hours":8.84,"date":"2027-03-18","moon_free_dark_hours":0.23,"moon_illumination":84,"moon_separation":54.7,"score":null,"score_astronomy":9,"score_weather":null,"transit_alt":42.9,"transit_local":"18:15","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.5,"best_label":"marginal","best_window":"20:05\u201321:35","dark_hours":8.79,"date":"2027-03-19","moon_free_dark_hours":0.0,"moon_illumination":92,"moon_separation":66.0,"score":null,"score_astronomy":11,"score_weather":null,"transit_alt":42.9,"transit_local":"18:10","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.5,"best_label":"marginal","best_window":"20:10\u201321:40","dark_hours":8.73,"date":"2027-03-20","moon_free_dark_hours":0.0,"moon_illumination":97,"moon_separation":77.8,"score":null,"score_astronomy":13,"score_weather":null,"transit_alt":42.9,"transit_local":"18:05","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.25,"best_label":"good","best_window":"20:10\u201320:25","dark_hours":8.68,"date":"2027-03-21","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":89.8,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":42.9,"transit_local":"18:00","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.75,"best_label":"good","best_window":"20:10\u201320:55","dark_hours":8.63,"date":"2027-03-22","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":101.6,"score":null,"score_astronomy":20,"score_weather":null,"transit_alt":42.9,"transit_local":"18:00","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.83,"best_label":"good","best_window":"20:10\u201321:00","dark_hours":8.58,"date":"2027-03-23","moon_free_dark_hours":0.03,"moon_illumination":97,"moon_separation":112.9,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":42.9,"transit_local":"17:55","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.92,"best_label":"good","best_window":"20:15\u201321:10","dark_hours":8.53,"date":"2027-03-24","moon_free_dark_hours":1.2,"moon_illumination":92,"moon_separation":123.4,"score":null,"score_astronomy":25,"score_weather":null,"transit_alt":42.9,"transit_local":"17:50","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.83,"best_label":"good","best_window":"20:15\u201321:05","dark_hours":8.47,"date":"2027-03-25","moon_free_dark_hours":2.35,"moon_illumination":86,"moon_separation":132.8,"score":null,"score_astronomy":24,"score_weather":null,"transit_alt":42.9,"transit_local":"17:45","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.75,"best_label":"good","best_window":"20:15\u201321:00","dark_hours":8.42,"date":"2027-03-26","moon_free_dark_hours":3.47,"moon_illumination":78,"moon_separation":140.4,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":42.9,"transit_local":"17:40","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.58,"best_label":"good","best_window":"20:20\u201320:55","dark_hours":8.37,"date":"2027-03-27","moon_free_dark_hours":4.47,"moon_illumination":70,"moon_separation":145.5,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":42.9,"transit_local":"17:40","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.58,"best_label":"good","best_window":"21:20\u201321:55","dark_hours":8.31,"date":"2027-03-28","moon_free_dark_hours":5.35,"moon_illumination":60,"moon_separation":147.1,"score":null,"score_astronomy":19,"score_weather":null,"transit_alt":42.9,"transit_local":"18:35","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.5,"best_label":"good","best_window":"21:20\u201321:50","dark_hours":8.26,"date":"2027-03-29","moon_free_dark_hours":6.1,"moon_illumination":51,"moon_separation":144.9,"score":null,"score_astronomy":17,"score_weather":null,"transit_alt":42.9,"transit_local":"18:30","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.42,"best_label":"good","best_window":"21:20\u201321:45","dark_hours":8.2,"date":"2027-03-30","moon_free_dark_hours":6.7,"moon_illumination":42,"moon_separation":139.6,"score":null,"score_astronomy":15,"score_weather":null,"transit_alt":42.9,"transit_local":"18:25","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.25,"best_label":"good","best_window":"21:25\u201321:40","dark_hours":8.15,"date":"2027-03-31","moon_free_dark_hours":7.2,"moon_illumination":32,"moon_separation":132.3,"score":null,"score_astronomy":13,"score_weather":null,"transit_alt":42.9,"transit_local":"18:25","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.25,"best_label":"good","best_window":"21:25\u201321:40","dark_hours":8.1,"date":"2027-04-01","moon_free_dark_hours":7.62,"moon_illumination":24,"moon_separation":123.7,"score":null,"score_astronomy":12,"score_weather":null,"transit_alt":42.9,"transit_local":"18:20","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.17,"best_label":"good","best_window":"21:25\u201321:35","dark_hours":8.04,"date":"2027-04-02","moon_free_dark_hours":7.97,"moon_illumination":16,"moon_separation":114.2,"score":null,"score_astronomy":10,"score_weather":null,"transit_alt":42.9,"transit_local":"18:15","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.08,"best_label":"good","best_window":"21:25\u201321:30","dark_hours":7.99,"date":"2027-04-03","moon_free_dark_hours":7.97,"moon_illumination":10,"moon_separation":104.2,"score":null,"score_astronomy":9,"score_weather":null,"transit_alt":42.9,"transit_local":"18:10","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":0.42,"best_label":"marginal","best_window":"21:30\u201321:55","dark_hours":7.93,"date":"2027-04-04","moon_free_dark_hours":7.92,"moon_illumination":5,"moon_separation":93.7,"score":null,"score_astronomy":7,"score_weather":null,"transit_alt":42.9,"transit_local":"18:05","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":0.42,"best_label":"marginal","best_window":"21:30\u201321:55","dark_hours":7.87,"date":"2027-04-05","moon_free_dark_hours":7.85,"moon_illumination":1,"moon_separation":83.0,"score":null,"score_astronomy":6,"score_weather":null,"transit_alt":42.9,"transit_local":"18:05","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":0.33,"best_label":"marginal","best_window":"21:30\u201321:50","dark_hours":7.82,"date":"2027-04-06","moon_free_dark_hours":7.8,"moon_illumination":0,"moon_separation":72.1,"score":null,"score_astronomy":5,"score_weather":null,"transit_alt":42.9,"transit_local":"18:00","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":0.25,"best_label":"marginal","best_window":"21:30\u201321:45","dark_hours":7.76,"date":"2027-04-07","moon_free_dark_hours":7.75,"moon_illumination":1,"moon_separation":61.3,"score":null,"score_astronomy":4,"score_weather":null,"transit_alt":42.9,"transit_local":"17:55","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":0.17,"best_label":"marginal","best_window":"21:00\u201321:10","dark_hours":7.71,"date":"2027-04-08","moon_free_dark_hours":7.35,"moon_illumination":5,"moon_separation":51.0,"score":null,"score_astronomy":3,"score_weather":null,"transit_alt":42.9,"transit_local":"17:50","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":7.65,"date":"2027-04-09","moon_free_dark_hours":6.08,"moon_illumination":10,"moon_separation":41.9,"score":null,"score_astronomy":2,"score_weather":null,"transit_alt":42.9,"transit_local":"17:45","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":0.0,"best_label":null,"best_window":null,"dark_hours":7.59,"date":"2027-04-10","moon_free_dark_hours":4.85,"moon_illumination":18,"moon_separation":35.3,"score":null,"score_astronomy":1,"score_weather":null,"transit_alt":42.9,"transit_local":"17:45","verdict":"unknown","weather_source":"none","weekday":"Sat"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2027-03-12","target":{"common_name":"Great Orion Nebula","dec":-5.3876,"name":"M 42","ra":83.8201,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=M42","source":"sesame","type":"HII","type_text":"HII region \u2014 a star-forming nebula"}}