Search results
Results From The WOW.Com Content Network
Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering 70.8% of Earth's crust.
Earth's circumference is the distance around Earth. Measured around the equator, it is 40,075.017 km (24,901.461 mi). Measured passing through the poles, the circumference is 40,007.863 km (24,859.734 mi). Measurement of Earth's circumference has been important to navigation since ancient times.
The Earth's radius is the distance from Earth's center to its surface, about 6,371 km (3,959 mi). While "radius" normally is a characteristic of perfect spheres, the Earth deviates from spherical by only a third of a percent, sufficiently close to treat it as a sphere in many contexts and justifying the term "the radius of the Earth".
Earth radius (denoted as R🜨 or ) is the distance from the center of Earth to a point on or near its surface. Approximating the figure of Earth by an Earth spheroid, the radius ranges from a maximum of nearly 6,378 km (3,963 mi) ( equatorial radius, denoted a) to a minimum of nearly 6,357 km (3,950 mi) ( polar radius, denoted b ).
In mathematics. In mathematics, the dimension of an object is, roughly speaking, the number of degrees of freedom of a point that moves on this object. In other words, the dimension is the number of independent parameters or coordinates that are needed for defining the position of a point that is constrained to be on the object.
pc ⋅ M⊙−1 ⋅ ( km / s) 2. The gravitational constant G is a key quantity in Newton's law of universal gravitation. The gravitational constant is an empirical physical constant involved in the calculation of gravitational effects in Sir Isaac Newton 's law of universal gravitation and in Albert Einstein 's theory of general relativity.
The gravity of Earth, denoted by g, is the net acceleration that is imparted to objects due to the combined effect of gravitation (from mass distribution within Earth) and the centrifugal force (from the Earth's rotation ). [2] [3] It is a vector quantity, whose direction coincides with a plumb bob and strength or magnitude is given by the norm .
An Earth mass (denoted as or , where 🜨 is the standard astronomical symbol for Earth ), is a unit of mass equal to the mass of the planet Earth. The current best estimate for the mass of Earth is M🜨 = 5.9722 × 1024 kg, with a relative uncertainty of 10 −4. [2] It is equivalent to an average density of 5515 kg/m3.