Eartha is the world's largest rotating and revolving

globe A globe is a spherical Earth, spherical Model#Physical model, model of Earth, of some other astronomical object, celestial body, or of the celestial sphere. Globes serve purposes similar to maps, but, unlike maps, they do not distort the surface ...

, located within the former headquarters of the

DeLorme DeLorme Publishing Company is a producer of personal satellite tracking, messaging, and navigation technology. The company's main product, ''inReach'', integrates GPS and satellite technologies. ''inReach'' provides the ability to send and rec ...

mapping corporation in

Yarmouth, Maine Yarmouth is a town in Cumberland County, Maine, United States, twelve miles north of the state's largest city, Portland, Maine, Portland. When originally settled in 1636, as North Yarmouth, Maine, North Yarmouth, it was part of the Massachusetts ...

Garmin Garmin Ltd. is an American multinational technology company based in Olathe, Kansas. The company designs, develops, manufactures, markets, and distributes GPS-enabled products and other navigation, communication, sensor-based, and information ...

purchased the company and the building in 2016. The globe weighs approximately 5,600 pounds (2,500 kg), and has a diameter of over 41 feet (12.5 m).

Construction

The globe was built with a scale of 1:1,000,000, on which one inch represents sixteen miles (1mm = 1km). As with most globes, it is mounted at a 23.5 degree angle, the same axial tilt as the Earth itself; thus the

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

is diagonal to the floor. It uses a

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

mount with two motors, and simulates one day's revolution and rotation every 18 minutes, though it is possible for the motors to fully rotate the globe in as little as one minute. Eartha 2023

The globe was completed in 1998, after two years of construction and planning, and it uses a composite database built from

satellite imagery Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell im ...

shaded relief Terrain cartography or relief mapping is the depiction of the shape of the surface of the Earth on a map, using one or more of several techniques that have been developed. Terrain or relief is an essential aspect of physical geography, and as su ...

, colored

bathymetry Bathymetry (; ) is the study of underwater depth of ocean floors ('' seabed topography''), river floors, or lake floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of wate ...

, and information about road networks and urban areas. The database used to generate the surface images was approximately 140

gigabyte The gigabyte () is a multiple of the unit byte for digital information. The SI prefix, prefix ''giga-, giga'' means 109 in the International System of Units (SI). Therefore, one gigabyte is one billion bytes. The unit symbol for the gigabyte i ...

s. Former CEO of DeLorme Maps, David DeLorme, designed the globe, while Lewiston-based surveyor and civil engineer, Vincent J.P. Leblanc, was involved in the building project. Map technician Jeff Clark was responsible for the 792 plastic sections that cover the rotating globe. Eartha is contained in an atrium with several glass walls that allow it to be seen from outside of the building; it is readily visible from

U.S. Route 1 U.S. Route 1 or U.S. Highway 1 (US 1) is a major north–south United States Numbered Highway that serves the East Coast of the United States. It runs from Key West, Florida, north to Fort Kent, Maine, at the Canadian border, ...

. At night, the globe is illuminated. Eartha is constructed around a

truss A truss is an assembly of ''members'' such as Beam (structure), beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so ...

structure which is called ''Omni-Span'', and consists of over 6000 pieces of aluminum tubing. The map panels each cover 8 degrees of

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

and 10 degrees of

longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...

, and are attached to the trusses with a custom-designed system of hidden bolts.

Public viewing

The atrium containing Eartha is open to the public during business hours. There was an adjacent coffee shop which, in 2016, replaced a gift shop that carried various DeLorme and geography-related products. A cafeteria returned at the time of Garmin's acquisition. The mounting equipment is in a large pit below floor level and is visible to visitors, but the stairway down is chained off to prevent public access. There are two balconies that allow visitors to more easily view the higher parts of the globe. Eartha was originally designed to be in diameter. In 1999,

surveyor Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. These points are usually on the ...

s hired by the ''

Guinness Book of World Records ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a British reference book published annually, listi ...

'' measured the globe at . The previous record holder is the

Globe of Peace A globe is a spherical model of Earth, of some other celestial body, or of the celestial sphere. Globes serve purposes similar to maps, but, unlike maps, they do not distort the surface that they portray except to scale it down. A model globe of ...

located in

Apecchio Apecchio is a ''comune'' (municipality) in the Province of Pesaro e Urbino in the Italian region Marche, about west of Ancona and about southwest of Pesaro Pesaro (; ) is a (municipality) in the Italy, Italian region of Marche, capital of t ...

Pesaro Pesaro (; ) is a (municipality) in the Italy, Italian region of Marche, capital of the province of Pesaro and Urbino, on the Adriatic Sea. According to the 2011 census, its population was 95,011, making it the second most populous city in the ...

, Italy.

References

Globes {{coord, 43.807922, N, 70.164008, W, display=title

Construction

Public viewing

See also

References