Gigametre
Encyclopedia
A gigametre is a unit
of length
in the metric system
, equal to one billion meters, the SI
base unit
of length, hence to 1,000,000 km
or approximately 621,370 mile
s.
Gigametres (from the Greek
words gigas = giant and metro = count/measure) are rarely seen in practical use, because they are too big for any terrestrial tasks. However, gigametres are sometimes used in astronomy
to measure the distance of companion objects such as planet
s from their star
s including our Sun
.
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...
of length
Length
In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...
in the metric system
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
, equal to one billion meters, the SI
International System of Units
The International System of Units is the modern form of the metric system and is generally a system of units of measurement devised around seven base units and the convenience of the number ten. The older metric system included several groups of units...
base unit
SI base unit
The International System of Units defines seven units of measure as a basic set from which all other SI units are derived. These SI base units and their physical quantities are:* metre for length...
of length, hence to 1,000,000 km
Kilometre
The kilometre is a unit of length in the metric system, equal to one thousand metres and is therefore exactly equal to the distance travelled by light in free space in of a second...
or approximately 621,370 mile
Mile
A mile is a unit of length, most commonly 5,280 feet . The mile of 5,280 feet is sometimes called the statute mile or land mile to distinguish it from the nautical mile...
s.
Gigametres (from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
words gigas = giant and metro = count/measure) are rarely seen in practical use, because they are too big for any terrestrial tasks. However, gigametres are sometimes used in astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
to measure the distance of companion objects such as planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s from their star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s including our Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
.
- One astronomical unitAstronomical unitAn astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
(AU) or EarthEarthEarth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's average distance from the Sun is 149.6 Gm. - JupiterJupiterJupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
's average distance from the Sun is 778.5 Gm. - The GJ 1214 b's average distance from the star GJ 1214GJ 1214GJ 1214 is a dim M4.5 red dwarf in the constellation Ophiuchus with an apparent magnitude of 14.7. It is located at a distance of approximately 40 light years from Earth. It is about one-fifth as large as the Sun with a surface temperature estimated to be...
is 2.14 Gm, which is the smallest orbit of any known exoplanets. - The mean diameter of the Sun is 1.391 Gm.
- The mean diameter of red supergiantRed supergiantRed supergiants are supergiant stars of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive...
star BetelgeuseBetelgeuseBetelgeuse, also known by its Bayer designation Alpha Orionis , is the eighth brightest star in the night sky and second brightest star in the constellation of Orion, outshining its neighbour Rigel only rarely...
is 1302 Gm.
See also
- 1 E+9 m1 E9 mTo help compare different distances this page lists lengths starting at 109 metres .Distances shorter than 109 metres* 1.4 Gm — Diameter of Sun...
- SISiSi, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
- SI prefixSI prefixThe International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
- Metric systemMetric systemThe metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
- Orders of magnitude (length)
- Conversion of unitsConversion of unitsConversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.- Process :...
, for comparison with other units of length - Light year
- ParsecParsecThe parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....