About Above Tonight
Above Tonight is a free interactive sky map that runs in your browser. It helps people find, name and share the sky above them: a real astronomical sky for any place, date and time you choose, with nothing to install and no account needed to look.
From background to common ground.
Why we make this
The sky is always there, and most of us stopped looking. It's one of the few things we all share: nobody made it, nobody owns it, and anyone in the same place at the same time sees the same one. Above Tonight helps you find it, name what you see, and send someone the exact sky you're looking at. Then we'd like you to put the phone down and go outside.
What it shows
The Sun, the Moon, the seven planets from Mercury to Neptune, 743 selectable stars and 88 constellation figures, drawn where they stand in the sky around you, above and below the horizon. Objects below the horizon are drawn too and marked as below it, because the Earth hides them. It lists rise and set times for the Sun, the Moon and the planets. You can search for an object and the view turns to it, and you can share the exact sky you are looking at as a link that opens the same place, date, time and view, paused at that moment.
Who makes it
Above Tonight is made and run by Filip Gruszecki.
How it works
The positions of the Sun, the Moon and the planets are calculated in your browser for the place and time you choose, with Astronomy Engine, version 2.1.19. The 743 selectable stars are a filtered extract adapted from HYG Database version 4.1 and reproduced from a pinned source pack. Constellation names and one Western line convention are adapted from D3-Celestial; the lines are not official International Astronomical Union boundaries. Cultural and naming notes are original editorial summaries, with their sources linked from each entry.
Drawn altitude and azimuth are geometric: they do not include atmospheric refraction. Rise and set times use Astronomy Engine's standard correction: about 34 arcminutes of atmospheric refraction at sea level, adjusted for the observer's elevation, timed to the top edge of the Sun and the Moon. The built-in city list is hand-compiled from public geographic coordinates and IANA time-zone identifiers, and a location taken from your device is rounded to 0.05 degrees before use. The plain-text documents below record the method, provenance, limits, attribution and licences.
What it does not do
Above Tonight shows where objects are, not what you will see. It has no model of weather, atmospheric visibility, light pollution, terrain, buildings or other obstructions, so an object drawn above the horizon may still be hidden. It does not identify an unknown object from a description or a photograph, and it does not draw aircraft, satellites, comets or meteors. It is a sky-viewing aid, not a navigation instrument. Never look directly at the Sun.
Corrections
Spotted a mistake in the sky, the data or the text? Write to hello@abovetonight.com.