Constellate

Pick a moment and a place. Constellate computes the sky as it actually stood there — every star down to the naked-eye limit, the constellation figures, the Moon at its true phase, and the planets that were above the horizon — and typesets it as a poster you can print. A REAL CALCULATION, NOT A DECORATION Positions come from the Yale Bright Star Catalog and the VSOP87 and ELP-2000 theories, with precession, nutation, aberration and local sidereal time all applied. Every position is checked against NASA JPL's Horizons ephemeris: the Sun and planets agree to better than one arcsecond, the Moon to about five. A printed dot at 300 DPI on an A2 sheet covers about a hundred arcseconds, so the map is right far below anything the paper can show. BUILT TO BE PRINTED Export a true vector PDF with the fonts embedded — sharp at any size, ready for a print shop, with 3 mm bleed. Or export a PNG at a…