Data Services

Rise/Set/Transit/Twilight Data

		Complete Sun and Moon Data for One Day
		Table of Sunrise/Sunset, Moonrise/Moonset, or Twilight Times for an Entire Year
		Rise/Set/Transit Times for Major Solar System Objects and Bright Stars includes altitude of object at transit and azimuth of object at rise and set
		Duration of Daylight/Darkness Table for One Year

Phases of the Moon

		Dates of Primary Phases of the Moon
		Fraction of the Moon Illuminated
		What the Moon Looks Like Today

Eclipses and Transits

		Eclipses of the Sun and Moon
		Solar Eclipse Computer computes circumstances for selected solar eclipses at any given location
		Lunar Eclipse Computer computes circumstances for selected lunar eclipses at any given location
		Recent and Upcoming Transits of Mercury and Venus
		Transit Computer computes circumstances for selected transits of Mercury and Venus at any given location

Positions of Selected Celestial Objects

		Altitude and Azimuth of the Sun or Moon During One Day
		Topocentric Configuration of Major Solar System Bodies provides tables of low precision topocentric position data for the Sun, Moon, and major planets
		Geocentric Positions of Major Solar System Objects and Bright Stars provides high precision geocentric position data for the Sun, Moon, major planets and selected bright stars.
		Topocentric Positions of Major Solar System Objects and Bright Stars provides high precision topocentric position data for the Sun, Moon, major planets and selected bright stars.

Synthetic Views of the Earth and Solar System Bodies

		Day and Night Across the Earth creates synthetic views of the Earth's surface (in grayscale or color) for any date and time
		Apparent Disk of Solar System Object creates a synthetic image of the telescopic appearance of the Moon or other solar system object for specified date and time

Dates

		Earth's Seasons - Equinoxes, Solstices, Perihelion,and Aphelion 1992-2020
		Spring Phenomena, 25 BCE to 38 CE
		Julian Date Conversion

Celestial Navigation

		Celestial Navigation Data provides computed altitudes and azimuths and other data for an assumed position and time
		Navigational Star Chart

Miscellaneous

		Astronomical Almanac Online provides complementary data to the printed Astronomical Almanac
		International Celestial Reference System (ICRS) - Important Links
		Occultations of Stars by Asteroids (International Occultation Timing Association)

DoD Information

DoD Information (restricted access)