An honest menu of the sky
StarsMenu answers one question: what can I actually see tonight, from here — from this window, this balcony, this city? Everything is worked out in your browser, for your place and your view of the sky.
How it works
Positions of the Sun, Moon and planets come from Astronomy Engine (accurate to about one arcminute), stars from the HYG catalogue, deep-sky objects from OpenNGC. Rise and set times include atmospheric refraction. The cloud forecast for the “go or no-go” verdict comes from several weather models at once — ECMWF, NOAA GFS and DWD ICON through Open-Meteo, and MET Norway — so the page can tell you when they disagree. If one service does not answer, the other is used.
My view turns the size and direction of your window or balcony into a map of the sky you can see. Every list and calendar on the site can then show only what passes through that patch of sky, and when.
The 3D Solar System and the Moon atlas compute their own ephemerides for any moment from 3000 BC to AD 3000; their accuracy notes are on those pages.
How accurate is it?
- Planet and Moon positions: about 1′ for our era; rise and set times to within a minute or two (the real horizon, air temperature and pressure shift them a little).
- Star positions include precession and proper motion, so the sky of 2000 BC looks the way it really did, give or take a fraction of a degree for most bright stars.
- My view is geometry from the numbers you enter. A compass reading from a phone is often 5–10° off; the Sun check on the My view page is more reliable.
- Cloud forecasts are forecasts. We show them as they are and never promise a clear night.
Privacy
There are no accounts, no ads and no tracking cookies. Your place, your view, your theme and other settings are kept in your browser's storage on this device and nowhere else.
- To get a cloud forecast, the coordinates of your place, rounded to 0.1° (about 10 km), are sent to Open-Meteo and to MET Norway. Nothing else is sent; MET Norway keeps the IP address and the requested coordinates in its server logs.
- Object pages in the catalog load photos and short descriptions from Wikipedia, Wikimedia Commons and the CDS sky-survey service (or NASA SkyView when CDS does not answer); the cards on Tonight and in the lists load small photos from Wikimedia Commons. Those sites see a normal request from your browser.
- The eyepiece view and a strong zoom on the sky map ask CDS for the faint stars (and, in the eyepiece, the survey picture) of the patch of sky you point it at — sky coordinates only, nothing about you.
- “What's that light?” loads the orbits of bright satellites from CelesTrak: the same list for everyone, your place is not sent. The light pollution map comes from this site.
- Fonts (SIL Open Font License) and the 3D library Three.js are served from this site, not from third-party servers.
- Safari on iPhone can clear a site's storage after seven days without a visit. Keep the link from My view, or add StarsMenu to your Home Screen to keep settings longer.
Data and credits
- Positions and events: Astronomy Engine © Don Cross, MIT License.
- Stars: HYG Database v4.1 by David Nash (astronexus.com), CC BY-SA 4.0.
- Constellation figures, label positions and names, boundaries, the Milky Way outline and the Messier list: d3-celestial © 2015 Olaf Frohn, BSD 3-Clause License — compiled from the IAU constellation pages, the Catalogue of Constellation Boundary Data (Davenhall & Leggett 1989, VizieR VI/49), the Milky Way Outline Catalog by Jose R. Vieira, SEDS Messier data by Hartmut Frommert, and constellation names in other languages from Wikipedia.
- NGC, IC and Caldwell objects: OpenNGC by Mattia Verga, CC BY-SA 4.0.
- Light pollution: F. Falchi, P. Cinzano, D. Duriscoe, C. C. M. Kyba, C. D. Elvidge, K. Baugh, B. A. Portnov, N. A. Rybnikova, R. Furgoni, “The new world atlas of artificial night sky brightness”, Science Advances 2 (2016) e1600377; data: GFZ Data Services, CC BY-NC 4.0. StarsMenu shows a simplified version averaged over 5 km cells. Coastlines and lakes: Natural Earth (public domain).
- Bright satellites and the Space Station: orbits from CelesTrak, computed with satellite.js (MIT).
- Faint stars in the eyepiece view: the Tycho-2 Catalogue (Høg et al. 2000, ESA) and Gaia DR3 (ESA/Gaia/DPAC, CC BY-SA 3.0 IGO); shapes of nebulae and galaxies from DSS2 (STScI, Caltech, Palomar). All are served by the CDS, Strasbourg, through VizieR and hips2fits.
- Links to articles and images: Wikidata, CC0 1.0. Descriptions: Wikipedia, CC BY-SA 4.0. Images: Wikimedia Commons, each under its own licence and author, credited on the object page. Sky-survey photos: DSS2 colour (STScI, Caltech, Palomar), served by the CDS hips2fits service.
- Cities and time zones: GeoNames, CC BY 4.0.
- Cloud forecasts: Open-Meteo.com, CC BY 4.0, with models by ECMWF, NOAA (GFS) and DWD (ICON); and data from MET Norway (the Norwegian Meteorological Institute), NLOD 2.0 and CC BY 4.0. StarsMenu combines them into one forecast and shows where they disagree.
- Moon maps: NASA LRO LROC WAC and LOLA (NASA SVS CGI Moon Kit); feature names: IAU / USGS Gazetteer of Planetary Nomenclature.
- Planet and moon surfaces in the 3D model: NASA, public domain. Three.js, MIT License.
Our star, deep-sky and constellation data files (data/sky/) are derived from CC BY-SA sources and are shared under the same licence, CC BY-SA 4.0.
StarsMenu is a non-commercial project. “StarsMenu” is a working name.