What's new

2026-05-22: due to the removal of heat map functionality from the google maps API, I've had to disable the aurorae overlay. I hope to reimplement this in a few days.
2026-05-08: added Higashi-Hiroshima Observatory and VERA Iriki Station (both Japan)
2026-05-03: major bug fix - solar system object positions were not corrected for precession so were incorrect by about 50 arcsec per year away from 2000
2026-04-23: fixed a bug which caused the wrong local time to appear for users in time zones with non-whole-hour offsets from UTC
2026-04-13: added Dunsink Observatory (Ireland) and Knox College Observatory (USA)
2026-04-06: fixed solar system object ephemerides, broken since about 25 March due to a change in the URL of the API used to fetch them
2026-02-22: updated light pollution data to 2024 values, and included history of light pollution measurements in observatory pages
2026-02-01: added Winer Observatory (US) and the Rosse Telescope (Ireland)

2025-12-10: added Solar System viewer
2025-12-08: added Ckoirama Observatory (Chile)
2025-11-05: hour angles now displayed in sky view mouseover and object extended data
2025-01-18: added SOAR and Rubin observatories (both Chile)

2024-03-08: added Meudon Observatory (France)
2024-03-07: added Hale Pohaku (United States)
2024-02-20: updated light pollution data to 2022 values
2024-02-19: added an option to input multiple objects directly, in addition to via file upload
2024-02-18: added Italian version by combining machine translation with very basic knowledge of the language. Reports of errors are welcomed!
2024-02-14: replaced previous generic observatory locations at La Palma, La Silla, Paranal and Mauna Kea with locations of specific telescopes. See observatories list for details

2023-09-15: added Lulin (Taiwan) and Los Molinos (Uruguay) observatories
2023-09-06: added Bosscha Observatory (Indonesia)
2023-08-23: added TÜBİTAK National Observatory (Turkey)
2023-07-11: added Observatorio de Yebes (Spain)
2023-01-05: when saving charts, a PNG file is now written out instead of an SVG file
2023-01-02: old domain name observability.date has now expired.

2022-12-23: added Sharjah Optical Observatory (United Arab Emirates)
2022-12-20: observatory codes from the Minor Planet Center list can be used to set your observing location
2022-12-16: added Seoul National University (South Korea) and Usuda Deep Space Center (Japan) observatories
2022-11-10: airmass.org is now also available in Greek. Many thanks to Panagiotis Evangelopoulos of the Institute of Astrophyics at FORTH for the translation!
2022-07-06: added Iranian National Observatory
2022-06-15: moved to a new hosting provider. Hopefully this made no difference to anything but please let me know if you encounter any problems
2022-06-06: updated light pollution data to 2020 values
2022-02-18: added Thai National Observatory
2022-02-07: at the bottom of the chart page you can now find a list of the charts you've plotted and of any short links you've created

2021-12-16: added Kiso Observatory (Japan)
2021-09-14: fixed incorrect coordinates of Mount Ekar observatory; added Asiago (Italy) and Pointe Vénus (French Polynesia) observatories
2021-08-30: a text file containing a list of objects to be plotted can be uploaded, under "advanced options"
2021-08-14: added facility to find nice targets that are observable from the selected observatory and date
2021-08-07: the starting month of annual plots can be changed
2021-07-25: added a sky view chart
2021-07-21: added option to plot the number of hours an object spends above a given altitude, during astronomical night, sunless hours or 24-hour periods
2021-07-05: new URL, half the number of syllables: airmass.org! Old URLs should redirect seamlessly to the new site until the old domain expires.
2021-07-01: deep-sky object names can be edited
2021-06-29: upper and lower pointing limits can be displayed on daily chart
2021-04-23: added Anton Pannekoek Observatory (Netherlands)
2021-04-20: added Leoncito (Argentina) and Val d'Aosta (Italy) observatories
2021-04-08: added Dominion Radio Astrophysical Observatory (Canada)
2021-03-27: added Armagh Observatory (Northern Ireland)
2021-03-26: added option to display current auroral activity
2021-03-21: added Loiano (Italy) and Nishi-Harima (Japan) observatories
2021-03-19: added Bulgarian National and Metsähovi Radio (Finland) observatories
2021-03-02: added Moon viewer with feature labels
2021-02-13: updated light pollution data to 2016 values
2021-02-11: added clouds display to map
2021-02-04: added 7-day weather forecasts

2020-10-26: closed second user survey. Thanks for the comments and suggestions!
2020-08-11: multiple objects can now be plotted
2020-07-18: added facility to look up solar system objects
2020-07-11: added calculation of heliocentric velocity correction
2020-07-04: fixed coordinates of the AAO, removed duplicate entry under "Siding Spring"
2020-07-04: added Skinakas (Greece), Ishigaki (Japan) and Okayama (Japan) observatories
2020-06-29: added Dwingeloo Radio Telescope (Netherlands)
2020-06-28: added link to SIMBAD page for objects identified in the field
2020-06-27: fixed incorrect coordinates of Haleakala Observatory (United States)
2020-04-24: implemented night mode. Press d on a visibility page to try it.
2020-02-21: added National Observatories of Chile and Colombia
2020-02-08: added time conversions, live and hourly on the selected night
2020-02-07: Spanish and French language versions now available
2020-02-05: added list of observatories
2020-02-05: added display of lunar phase
2020-02-02: added Mullard Radio Astronomy Observatory (UK)
2020-02-01: added light pollution information
2020-01-31: major rewrite of underlying code to enable planned upgrades

2019-12-23: added Gordon Southam Observatory (Canada)
2019-12-13: added Pulkovo Observatory (Russia)
2019-12-04: added Wise (Israel) and Ali (China) observatories
2019-11-25: added Biruni Observatory (Iran)
2019-11-06: added Wendelstein Observatory (Germany)
2019-10-30: closed survey. The answers were very useful - thanks!
2019-10-28: added some Gemini instruments to FOV list
2019-10-27: added Vienna (Austria) and Vidojevica (Serbia) observatories, added La Silla instruments to FOV list
2019-10-26: added facility to show instrument fields of view
2019-10-19: added Nice observatory (France)
2019-10-17: UI improvements
2019-10-16: added observatories: Crimea (Ukraine), Potsdam (Germany), Girawali (India), Heidelberg (Germany), Peyton (United States), Indian Astronomical Observatory
2019-10-15: opened user survey
2019-08-25: added Pic du Midi observatory (France)
2019-06-28: added Molonglo (Australia)
2019-06-22: added Halley's Mount (St. Helena), SMA (United States) and LIGO Hanford and Livingston stations (both United States)
2019-06-18: added Pico dos Dias (Brazil)
2019-06-01: added Observatório Valongo (Brazil)
2019-05-21: night indicated on world map
2019-05-19: added Mount Abu (India)
2019-05-14: added MeerKAT (South Arica) and SAO-RAS (Russia)
2019-05-13: added current weather at the selected location from openweathermap.org, added Royal Observatory Edinburgh (Scotland)
2019-04-02: added APEX (Chile)
2019-03-11: added Murchison (Australia)
2019-03-07: added Mount John Observatory (New Zealand)
2019-03-03: added azimuth of object to daily chart
2019-01-15: added Olin Science Center (United States)

2018-11-16: added JCMT (United States)
2018-10-10: added Wright's Tower (UK)
2018-02-21: added Griffith Observatory (United States)
2018-02-17: initial release

Future development

Currently, I am developing and improving the Solar System viewer. After that, there are currently no major developments in the pipeline. Feature requests are very welcome - send any to rw@nebulousresearch.org!