Skycatching

The sky in this app is the sky above you right now computed from a catalogue of 119,625 stars, the planetary ephemeris, the date and where you are standing. Not a photograph, not a camera trick. Point the phone at the ceiling and it is still there, correct, through the building CATCH A STAR Point until the ring finds one, then press when the marker crosses the zone. That is the whole thing. A bright star is generous, a faint one is not, and that is the entire difficulty curve. THE CONSTELLATIONS ASSEMBLE THEMSELVES Catch both ends of a line and the line lights up. Orion draws itself in front of you over a few evenings, and the gaps are what send you back out. DRAW YOUR OWN The 88 are somebody else's drawing. Join stars you have caught into a shape of your own, name it, and it hangs on the sky beside the ones the Greeks left. A RECORD, NOT A SCORE Every star you hold keeps its catalogue entry — designation, spectral class, magnitude, distance, how high it ever gets from your latitude — and one line you wrote about the night you caught it. IT WORKS WHEREVER YOU ARE Noon, indoors, under cloud, in a lit city. The phone is a window onto the real sky rather than a mirror of what your eye can see. NOTHING LEAVES THE PHONE No account, no server, no analytics, no advertising. Your location is used to work out which stars are above your horizon and is never sent anywhere, because there is nowhere to send it.