Astronomy Tools

Find the Moon phase and illumination percentage for any past or future date. See a realistic lit Moon, its age in days, how far through the cycle it is, and the dates of the next New Moon, First Quarter, Full Moon and Last Quarter.

Estimate how well the stars will show tonight from your location. Combines the Bortle light-pollution scale with cloud cover, humidity and Moon phase for a 0-100 stargazing score, limiting magnitude and a live night-sky preview.

Calculate the sun's azimuth and elevation for any date, time and location. See it plotted on an interactive sky dome, trace the whole day's path, and get sunrise, solar noon, sunset, day length and shadow length.

Calculate sunrise, sunset, solar noon and day length for any location and date. See every twilight phase, the golden and blue hours, how fast day length is changing, and an animated sun-path arc with a day and night sky ribbon.

Estimate high and low tide times for any day from one known reference high tide. Projects the lunar tidal cycle forward and back, drawing a tide curve, a live tide clock and a daily table for semi-diurnal, diurnal and mixed patterns.