Lunar Eclipse Computer

This data service calculates the circumstances of recent and upcoming lunar eclipses . Use the following steps to find the visible circumstances at any given location:

Select the eclipse of interest from the drop-down list.
Specify the location of interest using the fields provided on the form. Use the buttons to find coordinates of cities or towns in the U.S. or its territories, or to convert between Degrees-Minutes-Seconds (DMS) and Decimal Degrees.
Click the "Get Data" button at the end of the form to compute a table of local circumstances.

Be sure to read Notes on the Data for an explanation of the items in the table.

For general information on eclipse circumstances and visibility, see Upcoming Eclipses of the Sun and Moon.

US Location For example: Washington, DC

City

State or Territory

The place name you enter above must be a city or town in the U.S. The place's location will be retrieved from a list of over 22,000 places. Either upper- or lower-case letters or a combination can be used. Spell out place name prefixes, as in "East Orange", "Fort Lauderdale", "Mount Vernon", etc. The only exception is "St.", which is entered as an abbreviation with a period, as in "St. Louis". You need only enter as many characters as will unambiguously identify the place.

Eclipse:

Location Coordinates in decimal degrees, North and East are positive. For example: 38.9072, -77.0369

Latitude

Longitude

Location Label Custom label for printed output. For example: Washington, DC

Need coordinates? Try NGA's GEOnet Names Server (GNS)
Need U.S. coordinates? Try the USGS Geographic Names Information System (GNIS) .

Time Zone Example: 5 hours West of Greenwich (UTC-5) is Eastern Standard Time

hours

direction

East of Greenwich (UTC)

West of Greenwich (UTC)

Need a time zone? Try the time zone map.

Notes

The table of local circumstances gives the local time of each eclipse "event" that is visible from the location. The times are the same as those published in The Astronomical Almanac, adjusted to the specified time zone. The altitude and azimuth of the Moon at each of the events is given as well. The azimuth is reckoned eastward from North. The altitude is corrected for refraction assuming standard atmospheric conditions.

The table also gives the time of moonrise immediately preceding, and the time of moonset immediately following, the eclipse. At high latitudes, either or both of these times may be missing from the table. The accuracy of the rise/set times decreases as the latitude approaches +/- 90 degrees. For information on the definitions of terms used, see Rise, Set, and Twilight Definitions

The times of all events are presented in the standard time of the location requested. Daylight time may be manually included by changing the specified zone.

More information on eclipses can be found at the Eclipses Online Portal .

If you need to check the times of sunrise and sunset around the time of the eclipse, see Complete Sun and Moon Data for One Day.

Time Zones

When using the "Need USA Location" button, the service will fill the Time Zone hours field and set the Time Zone direction button according to the current standard time zone of the US place entered.

The railroads introduced standardized time zones to the USA in 1883. Since then, time zone boundaries have evolved considerably, with many cities and counties shifting from one zone to another. This service makes no attempt to track such historical changes.

For locations that require it, you may enter the time zone in decimal hours. For example, for locations in India, you may enter 5.5 hours east of Greenwich for the time zone. The time zone field can accommodate up to five characters.