Navigating the Earth's invisible grid
It's a big world out there – all covered by an imaginary grid. This invented grid divides the Earth into degrees of latitude and longitude, which creates a universal standard for measuring location and time.
Q: What do latitude and longitude mean?
A: These imagined lines define specific locations through geographical coordinates by measuring the distance from the equator (which runs around the center of the Earth from east to west, and is 0 degrees latitude) and the prime meridian (which sits perpendicular to the equator and runs from north to south, and is 0 degrees longitude).
Latitude lines run parallel to the equator, and longitude lines are parallel to the prime meridian. Because the Earth is (basically) a sphere, it's divided into 360 latitude and longitude degrees.
Q: What are latitude and longitude used for?
A: Latitude and longitude are used to identify locations by specifying where they are in relation to the equator and prime meridian. There are a few different ways to write latitude and longitude coordinates, but latitude is always listed first, and longitude second. If latitude is positive, it's north of the equator, and if it's negative, it's south. Similarly, if longitude is positive, it's west of the equator, and if it's negative, it's east.
One of the most common ways to write latitude and longitude is with decimals. For example: New York City is located at 40.712784, -74.005941 – or 40.712784 degrees north of the equator and 74.005941 east of the prime meridian.
Q: How does someone use Google Maps to find latitude and longitude?
A: To find a place's coordinates on Google Maps on a computer, open the website and right-click the area you're interested in. Select "What's here?" and the bottom of the map will display a card with the coordinates.
On a smartphone, open the Google Maps app and touch and hold an unlabeled area of the map. A red pin will appear, and the place's coordinates will appear in the search box at the top.
Q: How accurate is Google Maps' latitude and longitude?
A: Google hasn't made any claims regarding the accuracy of its map's coordinates, but a representative said on a product forum in 2009 that the coordinates might be accurate only to 15 meters and that they "are provided for entertainment only and should not be used for any navigational or other purpose requiring any accuracy whatsoever."
NASA also provides an online tool for finding latitude and longitude coordinates. The agency uses signals from systems such as the U.S. Global Positioning System (GPS) to find coordinates which might be more accurate than Google's.