Pounds to Earth Masses (lb to M⊕)
1 pound equals 7.595063293×10⁻²⁶ Earth masses (rounded).
How to convert pounds to Earth masses
To convert pounds to Earth masses, multiply the number of pounds by 7.595063293×10⁻²⁶. The factor is rounded to 10 significant digits. To go the other way, multiply Earth masses by 1.316644722×10²⁵ (rounded).
Earth masses = pounds × 7.595063293×10⁻²⁶
Example: 10 pounds = 7.595063293×10⁻²⁵ Earth masses.
Approximate value. Standards for the Earth mass varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.
About these units
Pound (lb)
Exactly 0.45359237 kg, divided into 16 ounces. The standard unit of weight in the US and common in the UK.
Why is pound abbreviated lb? The answer is Roman. The English word comes from the Latin libra pondo, roughly the weight measured in libra, and the symbol keeps the first word. The Roman libra was divided into 12 unciae. The avoirdupois pound of 16 ounces came into general use around 1300 and was initially equal to 6,992 troy grains; under Elizabeth I it was redefined as 7,000 grains. The UK's Weights and Measures Act 1878 set the imperial standard pound as a platinum cylinder, and the troy pound was abolished for trade the following year.
Today the pound is defined from the kilogram. The International Yard and Pound Agreement of 1959 fixed it at exactly 0.45359237 kg, and the UK's Weights and Measures Act 1963 wrote the same figure into law. Pounds remain the everyday unit for body weight, groceries and shipping in the United States and are widely used in the UK. The word also survives in odd places: a six-pounder cannon was named for the weight of its shot, not its own.
1 pound = 0.45359237 kilograms (exactly).
Sources: Wikipedia: Pound (mass); NIST Guide to the SI, Appendix B.8 (mass conversions)
Earth Mass (M⊕)
About 5.9722×10²⁴ kg, the mass of the Earth. Used to compare planets.
Earth mass is the mass of our planet taken as a yardstick for others, and the best current estimate is about 5.9722 x 10^24 kg, with an uncertainty near one part in ten thousand. NASA's Earth fact sheet and the International Astronomical Union's recommended value agree with this figure.
No scale can weigh a planet, so the mass is found by dividing the planet's gravitational parameter by Newton's constant G. The parameter itself is known to about two parts in a billion from satellite tracking, but G is known only to roughly two parts in a hundred thousand, so the mass inherits that limit. For this reason astronomers often quote GM or mass ratios instead.
The history begins with Nevil Maskelyne's Schiehallion experiment in Scotland in the 1770s, whose result implied a density about one fifth too low. Henry Cavendish's laboratory torsion balance of 1798 produced a density within about 1 percent of the modern one. Uncertainty fell to about 0.2 percent by the 1890s. About 333,000 Earth masses make one solar mass.
1 Earth mass = 5.9722×10²⁴ kilograms (approximately).
Sources: Wikipedia: Earth mass; NASA Earth Fact Sheet
Related conversions
- Earth masses to pounds (reverse)
- Pounds to kilograms
- Pounds to grams
- Pounds to metric tons
- Pounds to ounces
- Pounds to milligrams
- Pounds to micrograms
- Pounds to carats
- Pounds to stone
- Pounds to short tons
- Pounds to long tons
- Pounds to troy ounces
- Pounds to daltons
- Kilograms to Earth masses
- Grams to Earth masses
- Metric tons to Earth masses
- Ounces to Earth masses
See all weight & mass units.