In order to report your observation of the night sky, you will need to know the geographic coordinates for your location, your latitude and longitude (Lat/Long). There will be an interactive lat/long locator available when entering your observations online at the "Report" page of this site. You will be able to use it:

1. either to see a location (lat/long) that you enter on a map to check that it is correct,
2. or to find a map of your location and get the lat/long from the map.

If you want to determine your location before making your night observations, you can use the following suggestions for finding your coordinates:

• A GPS unit outside at the location site. Report as many decimal places as the unit provides.
• Use the GLOBE at Night Webapp to find your latitude and longitude.
• Use a topographic map.
  

See the frequently asked questions below for more help in finding your Lat/Long.

Latitude describes your distance from Earth's equator and is measured in angular degrees, with 0 degrees being the equator.  The North Pole is +90 degrees and the South Pole is -90 degrees. Latitude is also described as being either “North” or “South,” depending on your position in relationship to the equator. 

Longitude is the angular measurement either east or west from the Prime Meridian, which runs through Greenwich, England.  Longitude increases as you leave the Prime Meridian (0 degrees) going east (0 to 180 degrees) and decreases as you head west (0 to -180 degrees), until they meet at 180 degrees.  Positive longitude values are also indicated by “East” and negative values are indicated by “West”.

It is very important that you use the correct directions in your coordinates!  Here are some guidelines:

Frequently Asked Questions:

“I have a GPS receiver or can borrow one.  How do I determine my location?”
Take the GPS receiver outside to the location where you are observing, and turn it on.  In a few seconds, the GPS receiver will display the coordinates.  You may need to refer to the Users’ Manual to set the receiver to display the coordinates, as some receivers also display your location on an electronic map.  Most receivers will display coordinates in either “Degrees, Minutes, and Seconds” or “Decimal Degrees.”  If you have a choice, select Decimal Degrees.  Be sure you understand which number is latitude and which is longitude!  When you record your location, it is critical to write down all the decimal places.  Your coordinates should have at least 4 or 5 decimal places.

“I don’t have a GPS receiver, but I know the street address.  What should I do?”

“I don’t know the street address, but I know one nearby.  How about me?”

“I want to observe from a remote location and there aren’t any addresses nearby.  Am I out of luck?”
All of these situations can be handled by the new GLOBE at Night web app. In the second section of the app is a map that will take a variety of inputs. If you are using a GPS enabled device such as a cell phone or tablet, the map will ask if it can use your location to locate where you are on the map. On any device (including a computer) you can input an address and the map will center on that address. You can further refine your location by panning the map and clicking (or touching) your location to place a marker. The app reports the latitude and longitude of the marker.

“I don’t have a GPS receiver or access to a Web browser?  Can I still participate?
Sure!  Try to find a topographic map of your location.  You can then use a ruler and a little math to determine your location.  If your school doesn’t have one, try a nearby library.  Many libraries have topographic maps of the local area, or know where to get one.