19th-century illustration of Archimedes' quip of "give me a lever long enough and a fulcrum on which to place it, and I will move the earth"[1]
General information
Unit system
astronomy
Unit of
mass
Symbol
M🜨
Conversions
1 M🜨in ...
... is equal to ...
SI base unit
(5.9722±0.0006)×1024 kg
U.S. customary
≈1.3166×1025 pounds
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. Using the nearest metric prefix, the Earth mass is approximately six ronnagrams, or 6.0 Rg.[3]
The Earth mass is a standard unit of mass in astronomy that is used to indicate the masses of other planets, including rocky terrestrial planets and exoplanets. One Solar mass is close to 333000 Earth masses. The Earth mass excludes the mass of the Moon. The mass of the Moon is about 1.2% of that of the Earth, so that the mass of the Earth+Moon system is close to 6.0456×1024 kg.
Most of the mass is accounted for by iron and oxygen (c. 32% each), magnesium and silicon (c. 15% each), calcium, aluminium and nickel (c. 1.5% each).
Precise measurement of the Earth mass is difficult, as it is equivalent to measuring the gravitational constant, which is the fundamental physical constant known with least accuracy, due to the relative weakness of the gravitational force. The mass of the Earth was first measured with any accuracy (within about 20% of the correct value) in the Schiehallion experiment in the 1770s, and within 1% of the modern value in the Cavendish experiment of 1798.
^ Attributed by Pappus of Alexandria (Synagoge [Συναγωγή] VIII, 4th century), as « Δός μοί ποῦ στῶ, καὶ κινῶ τὴν Γῆν ». Engraving from Mechanic's Magazine (cover of bound Volume II, Knight & Lacey, London, 1824).
^The cited value is the recommended value published by the International Astronomical Union in 2009 (see 2016 "Selected Astronomical Constants" Archived 15 February 2016 at the Wayback Machine in "The Astronomical Almanac Online" (PDF). USNO/UKHO. Archived from the original on 24 December 2016. Retrieved 8 February 2016.).
^Lawler, Daniel. "Earth now weighs six ronnagrams: New metric prefixes voted in". phys.org. Retrieved 21 November 2022.
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...
than it does on Earth because of the lower gravity, but it would still have the same mass. This is because weight is a force, while mass is the property...
drivers of Earth's tides. In geophysical terms the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter...
= (1.98847±0.00007)×1030 kg The solar mass is about 333000 times the mass of Earth (ME), or 1047 times the mass of Jupiter (MJ). The value of the gravitational...
material loosed from Earth after a Mars-sized object with about 10% of Earth'smass, named Theia, collided with Earth. It hit Earth with a glancing blow...
dwarfs and Neptune-mass planets. Earthmass (ME) is the unit of mass equal to that of the Earth. 1 ME = 5.9742×1024 kg. Earthmass is often used to describe...
(MJ) for large gas giant planets, and the mass of Earth (ME) for smaller rocky terrestrial planets. The mass of a planet within the Solar System is an...
the walls, on the roof, or that is entirely buried underground. Earth acts as thermal mass, making it easier to maintain a steady indoor air temperature...
seconds to hundreds of years. Mass wasting occurs on both terrestrial and submarine slopes, and has been observed on Earth, Mars, Venus, Jupiter's moon...
causes the object to orbit with the same period as Earth, in effect orbiting an Earth+Sun mass with the Earth-Sun barycenter at one focus of its orbit. The...
result was originally expressed as the relative density of Earth, or equivalently the mass of Earth. His experiment gave the first accurate values for these...
such as M🜨 for Earthmass. The earliest type of symbols are allegories, personifications or deifications, mostly in the form of an Earth goddess (in the...
(2009). "Proposals for the masses of the three largest asteroids, the Moon-Earthmass ratio and the Astronomical Unit". Celestial Mechanics and Dynamical Astronomy...
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mass at least 5.5 times that of the Earth, it is classified as a super-Earth (a category of planets with masses greater than Earth's up to ten Earth masses)...
frequency, G is the gravitational constant, and M is the mass of the planet. For the Earth 1/q ≈ 289, which is close to the measured inverse flattening...
4.64 LS), 109 times that of Earth. Its mass is about 330,000 times that of Earth, making up about 99.86% of the total mass of the Solar System. Roughly...
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...
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gravity. At the Earth's surface, an object whose mass is exactly one kilogram weighs approximately 9.81 newtons, the product of its mass and the gravitational...
billion years, the Earth–Moon system's center of mass will lie outside Earth, which would make it a double-planet system. The center of mass of the Jupiter–Sun...
extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified...
composition. Earth is included for comparison. Note that mass and radius values prefixed with "~" have not been measured, but are estimated from a mass-radius...
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