Orders of magnitude (length)

The following are examples of orders of magnitude for different lengths.

Objects of sizes in different order of magnitude.

Overview

Detailed list

To help compare different orders of magnitude, the following list describes various lengths between 1.6×10⁻³⁵ meters and meters.

Subatomic

Atomic to cellular

Cellular to human scale

Human to astronomical scale

Astronomical

Factor (m)	Multiple	Value	Item
106	1,000 km = 1 megametre (Mm)	2,390 km = 2.39 Mm	Diameter of dwarf planet Pluto, formerly the smallest planet category[note 2] in the Solar System
		3,480 km= 3.48 Mm	Diameter of the Moon
		5,200 km = 5.2 Mm	Typical distance covered by the winner of the 24 Hours of Le Mans automobile endurance race
		6,400 km = 6.4 Mm	Length of the Great Wall of China
		6,600 km = 6.6 Mm	Approximate length of the two longest rivers, the Nile and the Amazon
		7,821 km = 7.821 Mm	Length of the Trans-Canada Highway
		9,288 km = 9.288 Mm	Length of the Trans-Siberian Railway, longest in the world
107	10,000 km	12,756 km	Equatorial diameter of Earth
		40,075 km	Length of Earth's equator
108	100,000 km	142,984 km	Diameter of Jupiter
		299.792 km = 299 Mm	Distance traveled by light in one second
		384,000 km = 384 Mm	Moon's orbital distance from Earth
109	1 million km = 1 gigametre (Gm)	1,390,000 km = 1.39 Gm	Diameter of the Sun
		4,800,000 km = 4.8 Gm	Greatest mileage ever recorded by a car (3 million miles by a 1966 Volvo P-1800S, still driving)
1010	10 million km	18 million km	Approximately one light-minute
1011	100 million km	150 million km = 150 Gm	1 astronomical unit (AU); mean distance between Earth and Sun
		~ 900 Gm	Optical diameter of Betelgeuse (~600 × Sun)
1012	1 billion km = 1 terametre (Tm)	1.4 ×109 km = 1.4 Tm	Orbital distance of Saturn from Sun
		1.96 ×109 km = 1.96 Tm	Estimated optical diameter of VY Canis Majoris (1420 × Sun)
		2.3 ×109 km = 2.3 Tm	Estimated optical diameter of NML Cygni (1650 × Sun)
		2.37 ×109 km = 2.37 Tm	Median point of the optical diameter of UY Scuti, as of 2016 the largest known star
		5.9 ×109 km = 5.9 Tm	Orbital distance of Pluto from Sun
		~ 7.5 ×109 km = 7.5 Tm	Outer boundary of the Kuiper belt, inner boundary of the Oort cloud (~ 50 AU)
1013	10 Tm		Diameter of the Solar System as a whole[1]
		16.25×109 km = 16.25 Tm	Distance of the Voyager 1 spacecraft from Sun (as of Feb 2009), the farthest man-made object so far[32]
		62.03×109 km = 62.03 Tm	Estimated radius of the event horizon of the supermassive black hole in NGC 4889, the largest known black hole to date
1014	100 Tm	1.8×1011 km = 180 Tm	Size of the debris disk around the star 51 Pegasi [33]
		2×1011 km = 200 Tm	Total length of DNA molecules in all cells of an adult human body [34]
1015	1 petametre (Pm)	~ 7.5 ×1012 km = 7.5 Pm	Supposed outer boundary of the Oort cloud (~ 50,000 AU)
		9.46×1012 km = 9.46 Pm = 1 light year	Distance traveled by light in one year; at its current speed, Voyager 1 would need 17,500 years to travel this distance
1016	10 Pm	3.2616 light-years (3.0857×1013 km = 30.857 Pm)	1 parsec
		4.22 light-years = 39.9 Pm	Distance to nearest star (Proxima Centauri)
		4.37 light-years = 41.3 Pm	As of March 2013, distance to nearest discovered extrasolar planet (Alpha Centauri Bc)
1017	100 Pm	20.4 light-years = 193 Pm	As of October 2010, distance to nearest discovered extrasolar planet with potential to support life as we know it (Gliese 581 d)
		65 light-years = 6.15×1017 m = 615 Pm	Approximate radius of humanity's radio bubble, caused by high-power TV broadcasts leaking through the atmosphere into outer space
1018	1 exametre (Em)	200 light-years = 1.9 Em	Distance to nearby solar twin (HIP 56948), a star with properties virtually identical to our Sun [35]
1019	10 Em	1,000 light-years = 9.46 Em or 9.46 × 1015 km	Average thickness of Milky Way Galaxy[36] (1000 to 3000 ly by 21 cm observations[37])
1020	100 Em	12,000 light-years = 113.5 Em or 1.135 × 1017 km	Thickness of Milky Way Galaxy's gaseous disk[38]
	950 Em	100,000 light-years	Diameter of galactic disk of Milky Way Galaxy[1]
1021	1 zettametre (Zm)
		50 kiloparsecs	Distance to SN 1987A, the most recent naked eye supernova
		52 kiloparsecs = 1.62×1021 m = 1.62 Zm	Distance to the Large Magellanic Cloud (a dwarf galaxy orbiting the Milky Way)
		54 kiloparsecs = 1.66 Zm	Distance to the Small Magellanic Cloud (another dwarf galaxy orbiting the Milky Way)
		200 kiloparsecs = 6.15 Zm	Diameter of the low surface brightness disc halo of the giant spiral galaxy Malin 1
1022	10 Zm	13.25 Zm = 1.4 million light years = 600 kiloparsecs	Radius of the diffuse stellar halo of IC 1101, one of the largest known galaxies
		24 Zm = 2.5 million light-years = 770 kiloparsecs	Distance to Andromeda Galaxy
		3.26 million light-years =30.8 Zm = 1 megaparsec	1 megaparsec
		50 Zm (1.6 Mpc)	Diameter of Local Group of galaxies
1023	100 Zm	300–600 Zm = 10–20 megaparsecs	Distance to Virgo cluster of galaxies
1024	1 yottametre (Ym)	200 million light-years = 1.9 Ym = 61 megaparsecs	Diameter of the Local Supercluster and the largest voids and filaments.
		300 million light-years = 2.8 Ym = 100 megaparsecs	End of Greatness
		550 million light-years ~170 megaparsecs ~5 Ym	Diameter of the Horologium Supercluster[39]
		1 billion light-years = 9.46 Ym =306 megaparsecs	Diameter of the Pisces–Cetus Supercluster Complex, the supercluster complex where we live.
1025	10 Ym	1.37 billion light years = 1.3×1025 m = 13 Ym	Length of the Sloan Great Wall, a giant wall of galaxies (galactic filament).[40]
		3.26 billion light years =30.8 Ym = 1 gigaparsec	1 gigaparsec
		4 billion light years =37.84 Ym	Length of the Huge-LQG, a group of 73 quasars
1026	100 Ym	1×1010 light-years = 9.5×1025 m = 95 Ym	Estimated light travel distance to certain quasars. Length of the Hercules-Corona Borealis Great Wall, a colossal wall of galaxies, the largest and the most massive structure in the observable universe as of 2014.
		13.42 billion light years =1.27×1026 m = 127 Ym	Estimated light travel distance to UDFj-39546284, the most distant object ever observed
		9.2×1010 light years = 8.7×1026 m = 870 Ym	Approximate diameter (comoving distance) of the visible universe[1]
1027	1000 Ym	130 billion light years = 1.2×1027 m = 1200 Ym	Lower bound of the (possibly infinite) radius of the universe, if it is a 3-sphere, according to one estimate using the WMAP data at 95% confidence.[41] It equivalently implies that there are at minimum 21 particle horizon-sized volumes in the universe.
[note 3]	Ym	megaparsecs =  m = Ym	According to the laws of probability, the distance one must travel until one encounters a volume of space identical to our observable universe with conditions identical to our own.[42][43]
[note 3]	Ym	Mpc =  m = Ym	Maximum size of universe after cosmological inflation, implied by one resolution of the No-Boundary Proposal[44]

1 yoctometre

This Wikipedia series on orders of magnitude does not have a range of shorter distances

 To help compare different orders of magnitude this section lists lengths shorter than 10⁻²³ m (10 ym).

• 1.6 × 10⁻¹¹ yoctometres (1.6 × 10⁻³⁵ metres) – the Planck length (Measures of distance shorter than this are considered nonsensical and do not make any physical sense, according to current theories of physics).
• 1 ym – 1 yoctometre, the smallest named subdivision of the metre in the SI base unit of length, one septillionth of a metre.
• 1 ym – length of a neutrino.

10 yoctometres

To help compare different orders of magnitude this section lists lengths between 10⁻²³ metres and 10⁻²² metres (10 ym and 100 ym).

• 20 ym – the effective cross-section radius of 1 MeV neutrinos as measured by Clyde Cowan and Frederick Reines

100 yoctometres

To help compare different orders of magnitude this section lists lengths between 10⁻²² m and 10⁻²¹ m (100 ym and 1 zm).

• 100 ym – length of a top quark, one of the smallest known quarks

1 zeptometre

To help compare different orders of magnitude this section lists lengths between 10⁻²¹ m and 10⁻²⁰ m (1 zm and 10 zm).

• 2 zm – length of a preon, hypothetical particles proposed as subcomponents of quarks and leptons; the upper bound for the width of a cosmic string in string theory.
• 2 zm – radius of effective cross section for a 20 GeV neutrino scattering off a nucleon
• 7 zm – radius of effective cross section for a 250 GeV neutrino scattering off a nucleon

10 zeptometres

To help compare different orders of magnitude this section lists lengths between 10⁻²⁰ m and 10⁻¹⁹ m (10 zm and 100 zm).

• 15 zm – length of a high energy neutrino
• 30 zm – length of a bottom quark

100 zeptometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁹ m and 10⁻¹⁸ m (100 zm and 1 am).

• 177 zm – de Broglie wavelength of protons at the Large Hadron Collider (7 TeV as of 2010)

1 attometre

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁸ m and 10⁻¹⁷ m (1 am and 10 am).

• 1 am – sensitivity of the LIGO detector for gravitational waves
• 1 am – Upper limit for the size of quarks and electrons
• 1 am – Upper bound of the typical size range for "fundamental strings"
• 1 am – length of an electron
• 1 am – length of an up quark
• 1 am – length of a down quark

10 attometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁷ m and 10⁻¹⁶ m (10 am and 100 am).

• 10 am – range of the weak force

100 attometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁶ m and 10⁻¹⁵ m (100 am and 1 fm).

• 100 am – all lengths shorter than this distance are not conformed in terms of size
• 850 am – approximate proton radius

1 femtometre

The femtometre (American spelling: femtometer; symbol fm) is a unit of length in the metric system, equal to 10⁻¹⁵ metres. In particle physics, this unit is more commonly called a fermi, also with abbreviation "fm". To help compare different orders of magnitude this section lists lengths between 10⁻¹⁵ metres and 10⁻¹⁴ metres (1 femtometre (fm) and 10 fm).

• 1 fm – length of a proton
• 1 fm – length of a neutron
• 1.5 fm – diameter of the scattering cross section of an 11 MeV proton with a target proton
• 2.81794 fm – classical electron radius
• 7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a 6 MeV alpha particle over 140 degrees

10 femtometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁴ m and 10⁻¹³ m (10 fm and 100 fm).

• 1.75 to 15 fm – Diameter range of the atomic nucleus

100 femtometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹³ m and 10⁻¹² m (100 fm and 1 pm).

• ? – Compton wavelength of electron

1 picometre

To help compare different orders of magnitude this section lists lengths between 10⁻¹² and 10⁻¹¹ m (1 pm and 10 pm).

• 1 pm – distance between atomic nuclei in a white dwarf
• 2.4 pm – The Compton wavelength of the electron.
• 5 pm – shorter X-ray wavelengths (approx.)

10 picometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹¹ and 10⁻¹⁰ m (10 pm and 100 pm).

• 10 pm – side of a square with area 100 pm²
• 25 pm – radius of a helium atom
• 50 pm – radius of a hydrogen atom
• 50 pm – radius of an oxygen atom
• 50 pm – bohr radius
• ~50 pm – best resolution of a high-resolution transmission electron microscope
• 60 pm – radius of a carbon atom
• 93 pm – length of a dicarbon molecule

100 picometres

To help compare different orders of magnitude this section lists lengths between 10⁻¹⁰ and 10⁻⁹ m (100 pm and 1 nm).

• 100 pm – 1 Ångström
• 100 pm – covalent radius of sulfur atom
• 120 pm – van der Waals radius of a neutral hydrogen atom
• 120 pm – radius of a gold atom
• 126 pm – covalent radius of ruthenium atom
• 135 pm – covalent radius of technetium atom
• 150 pm – Length of a typical covalent bond (C–C)
• 153 pm – covalent radius of silver atom
• 155 pm – covalent radius of zirconium atom
• 175 pm – covalent radius of thulium atom
• 200 pm – highest resolution of a typical electron microscope
• 225 pm – covalent radius of caesium atom
• 280 pm – Average size of the water molecule
• 298 pm – radius of a caesium atom, the largest known atom.
• 340 pm – thickness of single layer graphene
• 356.68 pm – width of diamond cell (unit cell)
• 403 pm – width of lithium fluoride cell
• 500 pm – Width of protein α helix
• 543 pm – silicon lattice spacing
• 560 pm – width of sodium chloride cell
• 700 pm – width of glucose molecule
• 780 pm – mean width of quartz cell
• 820 pm – mean width of ice cell
• 900 pm – mean width of coesite cell
• 1000 pm – length of a Buckyball

1 nanometre

To help compare different orders of magnitude this section lists lengths between 10⁻⁹ and 10⁻⁸ m (1 nm and 10 nm).

• 1 nm –10 Ångströms
• 1 nm – side of square with area of 1 nm²
• 1 nm – edge of cube with volume 1 nm³
• 1 nm – diameter of a carbon nanotube
• 1 nm – roughly the length of a sucrose molecule, calculated by Albert Einstein
• 2.3 nm – length of a phospholipid
• 2.3 nm – Smallest microprocessor transistor gate oxide thickness
• 3 nm – width of a DNA helix
• 3 nm – flying height of the head of a hard disk
• 3.4 nm – length of a DNA turn (10 bp)
• 3.8 nm – size of an albumin protein molecule
• 5 nm – size of the gate length of a 16 nm processor
• 6 nm – length of a phospholipid bilayer
• 6-10 nm – thickness of cell membrane
• 6.8 nm – width of a haemoglobin molecule
• 10 nm Thickness of cell wall in Gram-negative bacteria

10 nanometres

To help compare different orders of magnitude this section lists lengths between 10⁻⁸ and 10⁻⁷ m (10 nm and 100 nm).

• 10 nm – 100 angstrom
• 10 nm – side of square of area 10⁻¹⁶ m²
• 10 nm – edge of cube of area 6 * 10⁻¹⁶ m² and volume 10⁻²⁴ m³
• 10 nm – radius of circle of area 3.14 * 10⁻¹⁶ m²
• 10 nm – radius of sphere of area 12.56 * 10⁻¹⁶ m² and volume 4.19 * 10⁻²⁴ m³
• 10 nm – the average length of a nanowire
• 10 nm – lower size of tobacco smoke^[45]
• 11 nm – the average half-pitch of a memory cell speculated to be manufactured in 2015.
• 13 nm – the length of the wavelength that is used for EUV lithiography
• 14 nm – Length of a porcine circovirus
• 15 nm – Length of an antibody
• 16 nm – technology is projected to be reached by semiconductor companies in the 2013 timeframe
• 18 nm – diameter of tobacco mosaic virus^[46] (Generally, viruses range in size from 20 nm to 450 nm.)
• 20 nm – Length of a nanobe, could be one of the smallest forms of life
• 20 nm to 80 nm – thickness of cell wall in Gram-positive bacteria^[47]
• 20 nm – thickness of bacterial flagellum
• 22 nm – the average half-pitch of a memory cell expected to be manufactured at around the 2011–2011 time frame.
• 22 nm – Smallest feature size of production microprocessors in September 2009^[48]
• 30 nm – lower size of cooking oil smoke
• 32 nm – the average half-pitch of a memory cell manufactured at around the 2009–2010 time frame.
• 40 nm – extreme ultraviolet wavelength
• 45 nm – the average half-pitch of a memory cell manufactured at around the 2007–2008 time frame.
• 50 nm – upper size for airborne virus particles
• 50 nm – flying height of the head of a hard disk^[49]
• 65 nm – the average half-pitch of a memory cell manufactured at around the 2005–2006 time frame.
• 58 nm – height of a T7 bacteriophage
• 90 nm – Length of a HIV virus
• 90 nm – Human immunodeficiency virus (HIV) (generally, viruses range in size from 20 nm to 450 nm)
• 90 nm – the average half-pitch of a memory cell manufactured at around the 2002–2003 time frame.
• 100 nm – Length of a Mesoporous silica.

100 nanometres

Comparison of sizes of semiconductor manufacturing process nodes with some microscopic objects and visible light wavelengths. At this scale, the width of a human hair is about 10 times that of the image.^[50]

To help compare different orders of magnitude this section lists lengths between 10⁻⁷ and 10⁻⁶ m (100 nm and 1 µm).

• 100 nm – greatest particle size that can fit through a surgical mask^[51]
• 100 nm – 90% of particles in wood smoke are smaller than this.
• 120 nm – greatest particle size that can fit through a ULPA filter
• 120 nm – diameter of a human immunodeficiency virus (HIV) ^[52]
• 125 nm – standard depth of pits on compact discs (width: 500 nm, length: 850 nm to 3.5 µm)
• 180 nm – typical length of the rabies virus
• 200 nm – typical size of a Mycoplasma bacterium, among the smallest bacteria
• 300–400 nm – near ultraviolet wavelength
• 300 nm – greatest particle size that can fit through a HEPA (High Efficiency Particulate Air) filter (N100 removes up to 99.97% at 0.3 micrometres, N95 removes up to 95% at 0.3 micrometres)
• 400–420 nm – wavelength of violet light (see color and visible spectrum)
• 420–440 nm – wavelength of indigo light (see color and visible spectrum)
• 440–500 nm – wavelength of blue light (see color and visible spectrum)
• 500–520 nm – wavelength of cyan light (see color and visible spectrum)
• 520–565 nm – wavelength of green light (see color and visible spectrum)
• 565–590 nm – wavelength of yellow light (see color and visible spectrum)
• 590–625 nm – wavelength of orange light (see color and visible spectrum)
• 625–700 nm – wavelength of red light (see color and visible spectrum)
• 700–1.4 µm – wavelength of near-infrared radiation

1 micrometre

The silk for a spider's web is around 5-7 μ m wide.

To help compare different orders of magnitude this section lists some items with lengths between 10⁻⁶ and 10⁻⁵ m (between 1 and 10 micrometres, or µm).

• ~0.7–300 µm – wavelength of infrared radiation
• 1 µm – the side of square of area 10⁻¹² m²
• 1 µm – edge of cube of volume 10⁻¹⁸ m³ (1 fL)
• 1–10 µm – diameter of a typical bacterium
• 1 µm – length of a lysosome
• 2 µm – length of an average E. coli bacteria
• 3–4 µm – size of a typical yeast cell^[53]
• 5 µm – length of a typical human spermatozoon's head ^[54]
• 6 µm – anthrax spore
• 7 µm – diameter of the nucleus of a typical eukaryotic cell
• about 7 μm – diameter of human red blood cells ^[55]
• 3–8 µm – width of strand of spider web silk^[56]
• 8 µm – width of a chloroplast
• 9 µm – thickness of the tape in a 120-minute compact cassette.
• about 10 µm – size of a fog, mist or cloud water droplet

10 micrometres

Fog particles are around 10-50 µm long.

To help compare different orders of magnitude, this section lists lengths between 10⁻⁵ m and 10⁻⁴ m (10 µm and 100 µm).

• 10 µm – width of cotton fibre^[57]
• 10 µm – transistor width of the Intel 4004, the world's first commercial microprocessor
• 10 µm – mean longest dimension of a human red blood cell
• 5–20 µm – dust mite excreta^[58]
• 10.6 µm – wavelength of light emitted by a carbon dioxide laser
• 15 µm – width of silk fibre
• 17 µm – minimum width of a strand of human hair^[21]
• 17.6 µm – one twip, a unit of length in typography
• 10 to 55 µm – width of wool fibre^[57]
• 25.4 µm – 1/1000 inch, commonly referred to as 1 mil in the U.S. and 1 thou in the UK
• 30 µm – length of a human skin cell
• 50 µm – typical length of Euglena gracilis, a flagellate protist
• 50 µm – typical length of a human liver cell, an average-sized body cell
• 50 µm – length of a silt particle
• 60 µm – length of a sperm cell
• 70 to 180 µm – thickness of paper

100 micrometres

A paramecium is around 300 µm long.

To help compare different orders of magnitude, this section lists lengths between 10⁻⁴ m and 10⁻³ m (100 µm and 1 mm). The term Myriometre (equivalent to 100 micrometers) is deprecated; the decimal metric prefix myrio-^[59] is obsolete^[60][61][62] and not included among the prefixes when the International System of Units was introduced in 1960.

• 100 µm – 1/10 of a millimetre
• 100 µm – 0.00394 inches
• 100 µm – smallest distance that can be seen with the naked eye
• 100 µm – average diameter of a strand of human hair^[21]
• 100 µm – thickness of a coat of paint
• 100 µm – length of a dust particle
• 110 µm – halfway between the Planck scale and the diameter of the Observable universe, √(8.8×10²⁶meters/1.6×10⁻³⁵meters) × 1.6×10⁻³⁵ meters=110 µm
• 120 µm – diameter of a human ovum
• 170 µm – length of the largest sperm cell in nature, belonging to the Drosophila bifurca fruit fly^[63][64]
• 181 µm – maximum width of a strand of human hair^[21]
• 100–400 µm – length of Demodex mites living in human hair follicles
• 200 µm – typical length of Paramecium caudatum, a ciliate protist
• 250–300 µm – length of a dust mite^[65]
• 340 µm – length of a single pixel on a 17-inch monitor with a resolution of 1024×768
• 500 µm – typical length of Amoeba proteus, an amoeboid protist
• 500 µm – MEMS micro-engine
• 500 µm – average length of a grain of sand
• 500 µm – average length of a grain of salt
• 500 µm – average length of a grain of sugar
• 560 µm – thickness of the central area of a human cornea^[66]
• 750 µm – diameter of a Thiomargarita namibiensis, the largest bacteria known^[67]
• 760 µm – thickness of an identification card

1 millimetre

An average ant is about 3-4 mm long.

To help compare different orders of magnitude this section lists lengths between 10⁻³ m and 10⁻² m (1 mm and 1 cm).

• 1.0 mm – 1/1000 of a metre
• 1.0 mm – 0.03937 inches or 5/127 (exactly)
• 1.0 mm – side of square of area 1 mm²
• 1.0 mm – diameter of a pinhead
• 1.5 mm – length of average flea^[23]
• 2.0 mm – length of a sugar cube
• 2.54 mm – distance between pins on old DIP (dual-inline-package) electronic components
• 5 mm – length of an average red ant
• 5 mm – diameter of an average grain of rice
• 5.56×45mm NATO – standard ammunition size
• 6 mm – approximate width of a pencil
• 7 mm – length of a Paedophryne amauensis, the smallest known vertebrate^[68]
• 7.1 mm – length of a sunflower seed
• 7.62×51mm NATO – common military ammunition size^[69]
• 8 mm – width of old-format home movie film
• 8 mm – length of a Paedocypris progenetica, the smallest known fish^[70]

1 centimetre

An average human fingernail is about 1 cm wide.

To help compare different orders of magnitude this section lists lengths between 10⁻² m and 10⁻¹ m (1 cm and 10 cm).

• 1 cm – 10 millimeters
• 1 cm – 0.39 inches
• 1 cm – edge of square of area 1 cm²
• 1 cm – edge of cube of volume 1 ml
• 1 cm – length of a coffee bean
• 1 cm – approximate width of average fingernail
• 1.2 cm – length of a bee
• 1.2 cm – diameter of a dice
• 1.5 cm – length of a very large mosquito
• 1.6 cm – length of a Jaragua Sphaero, the smallest known reptile^[71]
• 1.7 cm – length of a Thorius arboreus, the smallest Salamander^[72]
• 2 cm – approximate width of an adult human finger
• 2.54 cm – 1 inch
• 3.1 cm – 1 attoparsec (10⁻¹⁸ parsecs)
• 3.4 cm – length of a quail egg^[73]
• 3.5 cm – width of film commonly used in motion pictures and still photography
• 4.3 cm – minimum diameter of a golf ball^[74]
• 5 cm – usual diameter of a chicken egg
• 5 cm – height of a Hummingbird, the smallest known bird
• 5.5 × 5.5 × 5.5 cm – dimensions of a 3x3x3 rubik's cube
• 6.1 cm – average height of an apple
• 7.3–7.5 cm – diameter of a baseball^[24]
• 8.6 cm × 5.4 cm – dimensions of a standard credit card^[75]
• 9 cm – length of a Speckled Padloper, the smallest known turtle

1 decimetre

An adult human foot is about 28 centimetres long.

To help compare different orders of magnitude this section lists lengths between 10 centimetres and 100 centimetres (10⁻¹ metre and 1 metre).

Conversions

10 centimetres (abbreviated to 10 cm) is equal to:

• 1 decimetre (dm), a term not in common use
• 100 millimetres
• 3.9 inches
• a side of a square of area 0.01 m²
• the edge of a cube with a volume of 6997100000000000000♠1×10⁻³ (one litre)

Wavelengths

• 10 cm = 1.0 dm – wavelength of the highest UHF radio frequency, 3 GHz
• 12 cm = 1.2 dm – wavelength of the 2.45 GHz ISM radio band
• 21 cm = 2.1 dm – wavelength of the 1.4 GHz hydrogen emission line, a hyperfine transition of the hydrogen atom
• 100 cm = 10 dm – wavelength of the lowest UHF radio frequency, 300 MHz

Human-defined scales and structures

• 10.16 cm = 1.016 dm – 1 hand used in measuring height of horses (4 inches)
• 12 cm = 1.2 dm – diameter of a Compact Disc (CD) (= 120 mm)
• 15 cm = 1.5 dm – length of a Bic pen with cap on
• 22 cm = 2.2 dm – diameter of a typical Association football (soccer ball)
• 30 cm = 3 dm – typical school-use ruler length (= 300 mm)
• 30.48 cm = 3.048 dm – 1 foot (measure)
• 60 cm = 6 dm – standard depth (front to back) of a domestic kitchen worktop in Europe (= 600 mm)
• 90 cm = 9 dm – average length of a rapier, a fencing sword^[25]
• 91.44 cm = 9.144 dm – one yard (measure)

Nature

• 10 cm = 1 dm – diameter of the human cervix upon entering the second stage of labour
• 11 cm = 1.1 dm – diameter of an average potato
• 15 cm = 1.5 dm – approximate size of largest beetle species
• 19 cm = 1.9 dm – length of a banana
• 29 cm = 2.9 dm – length of average human foot
• 29.98 cm = 2.998 dm – distance light travels in one nanosecond
• 31 cm = 3.1 dm – wingspan of largest butterfly species Ornithoptera alexandrae
• 46 cm = 4.6 dm – length of an average domestic cat
• 50 to 65 cm = 5–6.5 dm – a pizote's tail
• 66 cm = 6.6 dm – length of the longest pine cones (produced by the sugar pine^[76])

Astronomical

• 84 cm = 8.4 dm – approximate diameter of 2008 TS26, a meteoroid

1 metre

Leonardo da Vinci drew the Vitruvian Man within a square of side 1.83 metres and a circle about 1.2 metres in radius

To help compare different orders of magnitude this section lists lengths between one metre and ten metres. Light travels 1 metre in  ¹⁄_299,792,458, or 3.3356409519815E-9 of a second.

Conversions

1 metre is:

• 10 decimetres
• 100 centimetres
• 1,000 millimetres
• 39.37 inches
• 3.28 feet
• side of square with area 1 m²
• edge of cube with surface area 6 m² and volume 1 m³
• radius of circle with area 3.14 m²
• radius of sphere with surface area 12.56 m² and volume 4.19 m³

Human-defined scales and structures

• 1 m – approximate height of the top part of a doorknob on a door
• 1 m – diameter of a very large beach ball
• 1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4' 8½"
• 2.5 m – distance from the floor to the celling in an average residential house^[77]
• 2.7 m – length of the Starr Bumble Bee II, the smallest plane
• 2.77–3.44 m – wavelength of the broadcast radio FM band 87–108 MHz
• 3.05 m – the length of an old Mini
• 8.38 m – the length of a London Bus (Routemaster)

Sports

• 2.44 m – height of an association football goal^[78]
• 2.45 m – highest high jump by a human being (Javier Sotomayor)^[79]
• 3.05 m – (10 feet) height of the basket in basketball
• 8.95 m – longest long jump by a human being (Mike Powell)^[80]

Nature

• 1 m – height of Homo floresiensis (the "Hobbit")
• 1.15 m – a pizote (mammal)
• 1.37 m – average height of an Andamanese person
• 1.63 m – (5 feet 4 inches) (or 64 inches) - height of average US female human as of 2002 (source: US Centers for Disease Control and Prevention (CDC)).
• 1.75 m – (5 feet 8 inches) - height of average US male human as of 2002 (source: US CDC as per female above)
• 2.5 m – height of a sunflower
• 2.72 m – (8 feet 11 inches) - tallest known human being (Robert Wadlow)^[27]
• 3.63 m – the record wingspan for living birds (a wandering albatross)
• 5 m – length of an elephant
• 5.20 m – height of a giraffe^[81]
• 5.5 m – height of a Baluchitherium, the largest land mammal ever lived
• 7 m – wingspan of Argentavis, the largest flying bird known
• 7.50 m – approximate length of the human gastrointestinal tract

Astronomical

• 3–6 m – approximate diameter of 2003 SQ222, a meteoroid
• 4.1 m – diameter of 2008 TC3, a small asteroid that flew into the Earth's atmosphere on October 7, 2008.^[82]

1 decametre

A blue whale has been measured as 33 metres long; this drawing compares its length to that of a human diver and a dolphin

To help compare different orders of magnitude this section lists lengths between 10 metres and 100 metres.

Conversions

10 metres (very rarely termed a decametre which is abbreviated as dam) is equal to:

• 10 metres
• 100 decimetres
• 1,000 centimetres
• 10,000 millimetres
• 32.8 feet
• side of square with area 100 m²

Human-defined scales and structures

• 10 metres – wavelength of the highest shortwave radio frequency, 30 MHz
• 23 metres – height of the obelisk of the Place de la Concorde, Paris, France.
• 25 metres – wavelength of the broadcast radio shortwave band at 12 MHz
• 29 metres – height of the lighthouse at Savudrija, Slovenia.
• 31 metres – wavelength of the broadcast radio shortwave band at 9.7 MHz
• 34 metres – height of the Split Point Lighthouse in Aireys Inlet, Victoria, Australia.
• 40 metres – average depth beneath the seabed of the Channel tunnel
• 49 metres – wavelength of the broadcast radio shortwave band at 6.1 MHz
• 50 meters – length of a road train
• 55 metres – height of the Leaning Tower of Pisa
• 60 metres – height of Pyramid of Djoser
• 64 metres – wingspan of a Boeing 747-400
• 69 meters – wingspan of a Antonov An-124 Ruslan
• 70 metres – length of the Bayeux Tapestry
• 70 metres – width of a typical football field
• 77 meters – wingspan of a Boeing 747-8
• 88.40 metres – wingspan of the Antonov An-225 Mriya transport aircraft
• 93 meters – height of the Statue of Liberty
• 96 meters – height of Big Ben
• 100 metres – wavelength of the lowest shortwave radio frequency, 3 MHz

Sports

• 11 metres – approximate width of a doubles tennis court
• 15 metres – width of a standard FIBA basketball court
• 15.24 metres – width of an NBA basketball court (50 feet)
• 18.44 metres – distance between the front of the pitcher's rubber and the rear point of home plate on a baseball field (60 feet, 6 inches)^[83]
• 20 metres – length of cricket pitch (22 yards)^[84]
• 27.43 metres – distance between bases on a baseball field (90 feet)
• 28 metres – length of a standard FIBA basketball court
• 28.65 metres – length of an NBA basketball court (94 feet)
• 49 metres – width of an American football field (53⅓ yards)
• 59.436 metres – width of a Canadian football field (65 yards)
• 70 metres – typical width of soccer field
• 91 metres – length of American football field (100 yards, measured between the goal lines)
• 105 metres – length of football pitch (UEFA Stadium Category 3 and 4)

Nature

• 10 metres – average length of human digestive tract
• 12 metres – length of a whale shark, largest living fish
• 12 metres – wingspan of a Quetzalcoatlus, a pterosaur
• 13 metres – length of a giant squid and colossal squid, the largest living invertebrates
• 15 metres – approximate distance the tropical circles of latitude are moving towards the equator and the polar circles are moving towards the poles each year due to a natural, gradual decrease in the Earth's axial tilt
• 18 metres – height of a Sauroposeidon, the tallest known dinosaur
• 20 metres – length of a Leedsichthys, the largest known fish ever lived
• 21 metres – height of High Force waterfall in England
• 33 metres – length of a blue whale,^[85] the largest animal on earth, living or extinct, in terms of mass
• 35 metres – length of a Supersaurus, the longest known dinosaur and longest vertebrate
• 40 metres – average depth beneath the seabed of the Channel tunnel
• 52 metres – height of Niagara Falls^[29]
• 83.34 meters – height of a Western hemlock

Astronomical

• 30 metres – diameter of 1998 KY26, a rapidly spinning meteoroid
• 32 meters – approximate diameter of 2008 HJ, a small meteoroid

1 hectometre

The Great Pyramid of Giza is 138.8 metres high.

British driver location sign and location marker post on the M27 in Hampshire. The location marker posts are installed at 100-metre intervals^[86]

To compare different orders of magnitude this section lists lengths between 100 metres and 1000 metres (1 kilometre).

Conversions

100 metres (sometimes termed a hectometre) is equal to:

• 328 feet
• one side of a 1 hectare square
• a fifth of a modern li, a Chinese unit of measurement
• the approximate distance travelled by light in 300 nanoseconds

Human-defined scales and structures

• 100 metres – wavelength of the highest mediumwave radio frequency, 3 MHz
• 100 metres – spacing of location marker posts on British motorways
• 138.8 metres – height of the Great Pyramid of Giza (Pyramid of Cheops)
• 139 metres – height of the world's tallest roller coaster, Kingda Ka^[87]
• 187 metres– shortest wavelength of the broadcast radio AM band, 1600 kHz
• 202 metres – length of the Széchenyi Chain Bridge connecting Buda and Pest
• 318 meters – height of The New York Times Building
• 318.9 meters – height of the Chrysler Building
• 320.75 metres – height of the Eiffel Tower(including antenna) ^[88]
• 328 metres – height of Auckland's Sky Tower, the tallest free-standing structure in the Southern Hemisphere
• 341 metres – height of the world's tallest bridge, the Millau Viaduct
• 390 metres – height of the Empire State Building
• 400–800 metres – approximate heights of the world's tallest skyscrapers of the past 80 years
• 458 metres – length of the Knock Nevis, the world's largest supertanker
• 553.33 meters – height of the CN Tower^[89]
• 555 metres – longest wavelength of the broadcast radio AM band, 540 kHz
• 630 metres – height of the KVLY-TV mast, second tallest structure in the world
• 646 metres – height of the Warsaw radio mast, the world's tallest structure until its collapse in 1991
• 828 metres – height of Burj Khalifa, world's tallest structure on 17 January 2009^[90]
• 1,000 metres – wavelength of the lowest mediumwave radio frequency, 300 kHz

Sports

• 100 metres – the distance a very fast human being can run in about 10 seconds
• 100.584 metres – length of a Canadian football field between the goal lines (110 yards)
• 91.5 metres – 137 metres – length of a soccer field^[91]
• 105 metres – length of a typical football field
• 109.73 metres – total length of an American football field (120 yards, including the end zones)
• 110 – 150 metres the width of an Australian football field
• 135 – 185 metres the length of an Australian football field
• 137.16 metres – total length of a Canadian football field, including the end zones (150 yards)

Nature

• 115.5 metres – height of the world's tallest tree in 2007, the Hyperion sequoia^[92]
• 310 metres – maximum depth of Lake Geneva
• 340 metres – distance sound travels in air at sea level in one second; see speed of sound
• 979 metres – height of the Salto Angel, the world's highest free-falling waterfall (Venezuela)

Astronomical

• 270 metres – length of 99942 Apophis
• 535 metres – length of 25143 Itokawa,^[93] a small asteroid visited by a spacecraft

1 kilometre

Mount Fuji is 3.776 kilometres (3,776 metres) high

To help compare different orders of magnitude this section lists lengths between 1 kilometre and 10 kilometres (10³ and 10⁴ metres).

Conversions

1 kilometre (unit symbol km) is equal to:

• 1,000 metres
• 0.621371 miles
• 1,093.61 yards
• 3,280.84 feet
• 39,370.1 inches
• 100,000 centimetres
• 1,000,000 millimetres
• Side of a square of area 1 km².
• Radius of a circle of area π km².

Human-defined scales and structures

• 1 km – wavelength of the highest long wave radio frequency, 300 kHz^[94]
• 1.280 km – span of the Golden Gate Bridge (distance between towers)^[95]
• 1.609 km – 1 mile
• 1.852 km – 1 nautical mile, equal to 1 arc minute of latitude at the surface of the earth^[96]
• 1.991 km – span of the Akashi Kaikyō Bridge^[97]
• 2.309 km – axial length of the Three Gorges Dam, the largest dam in the world^[30]
• 3.991 km – length of the Akashi Kaikyō Bridge, longest suspension bridge in the world as of December 2008^[98]
• 5.072 km – height of Tanggula Mountain Pass, below highest peak in the Tanggula Mountains, highest railway pass in the world as of August 2005^[99]
• 5.727 km – height of Cerro Aucanquilcha, highest road in the world, located in Chile^[100]
• 98 airports have paved runways from 4 km to 5.5 km in length.
• 8 km – length of Palm Jebel Ali, an artificial island built off the coast of Dubai
• 9.8 km – length of The World, an artificial archipelago that is also built off the coast of Dubai, it's islands resemble a world map

Geographical

• 1.637 km – deepest dive of Lake Baikal in Russia, the world's largest fresh water lake.^[101]
• 2.228 km – height of Mount Kosciuszko, highest point in Australia^[102]
• Most of Manhattan is from 3 to 4 km wide.
• 4.810 km – height of Mont Blanc, highest peak in the Alps
• 4.884 km – height of Carstensz Pyramid, highest peak in Oceania^[103]
• 4.892 km – height of Mount Vinson, highest peak in Antarctica
• 5.610 km – height of Mount Damavand, highest peak in Iran
• 5.642 km – height of Mount Elbrus, highest peak in Europe
• 5.895 km – height of Mount Kilimanjaro, highest peak in Africa
• 6.081 km – height of Mount Logan, highest peak in Canada
• 6.194 km – height of Denali, highest peak in North America
• 6.959 km – height of Aconcagua, highest peak in South America
• 7.5 km – depth of Cayman Trench, deepest point in the Caribbean Sea
• 8.848 km – height of Mount Everest, highest peak on Earth, on the border between Nepal and China

Astronomical

• 1 km – diameter of 1620 Geographos
• 1 km – very approximate size of the smallest known moons of Jupiter
• 1.4 km – diameter of Dactyl, the first confirmed asteroid moon
• 4.8 km – diameter of 5535 Annefrank, an inner belt asteroid
• 5 km – diameter of 3753 Cruithne, one of the smallest asteroids
• 5 km – length of PSR B1257+12
• 8 km – diameter of Themisto, one of Jupiter's moons
• 8 km – diameter of the Vela Pulsar
• 8.6 km – diameter of Callirrhoe, also known as Jupiter XVII
• 9.737 km – length of PSR B1919+21

10 kilometers

The Strait of Gibraltar is 13 kilometres wide

To help compare different orders of magnitude this section lists lengths between 10 and 100 kilometres (10⁴ to 10⁵ metres). The myriametre^[104] (sometimes also spelled myriameter, myriometre and myriometer) (10,000 metres) is a deprecated unit name; the decimal metric prefix myria-^[59] (sometimes also written as myrio-^{[105][106][107]}) is obsolete^[60][61][62] and not included among the prefixes when the International System of Units was introduced in 1960.

Conversions

10 kilometres is equal to:

Distance marker on the Rhine: 36 (XXXVI) myriametres from Basel. Note that the stated distance is 360 km; comma is the decimal mark in Germany.

• 10,000 metres
• 6.2 miles
• 1 mil (the Scandinavian mile), now standardized as 10 km:
  • 1 mil, the unit of measure commonly used in Norway and Sweden^[108] used to be 11,295 m in Norway and 10,688 m in Sweden.
• farsang, unit of measure commonly used in Iran and Turkey.^[109]

Sports

• 42.195 km – length of the marathon^[110]

Human-defined scales and structures

• 18 km – cruising altitude of Concorde
• 27 km – circumference of the Large Hadron Collider, as of May 2010 the largest and highest energy particle accelerator
• 34.668 km – highest manned balloon flight (Malcolm D. Ross and Victor E. Prather on 4 May 1961) ^[111]
• 38.422 km – length of the Second Lake Pontchartrain Causeway in Louisiana, US
• 39 km – undersea portion of the Channel tunnel
• 53.9 km – length of the Seikan Tunnel, as of October 2009, the longest rail tunnel in the world^[112]
• 77 km – Rough total length of the Panama Canal^[113]

Geographical

• 10 km – height of Mauna Kea in Hawaii, measured from its base on the ocean floor
• 11 km – deepest known point of the ocean, Challenger Deep in the Mariana Trench
• 11 km – average height of the troposphere
• 14 km – width of the Gibraltar strait
• 21 km – length of Manhattan
• 23 km – depth of the largest earthquake ever recorded in the United Kingdom, in 1931 at the Dogger Bank of the North Sea
• 34 km – narrowest width of the English Channel at the Strait of Dover
• 50 km – approximate height of the stratosphere
• 90 km – width of the Bering Strait

Astronomical

• 10 km – diameter of the most massive neutron stars (3–5 solar masses)
• 13 km – mean diameter of Deimos, the smaller moon of Mars
• 20 km – diameter of the least massive neutron stars (1.44 solar masses)
• 20 km – diameter of Leda, one of Jupiter's moons
• 20 km – diameter of Pan, one of Saturn's moons
• 22 km – diameter of Phobos, the larger moon of Mars
• 27 km – height of Olympus Mons above the Mars reference level,^[114][115] the highest known mountain of the Solar System
• 43 km – diameter difference of Earth's equatorial bulge
• 66 km – diameter of Naiad, the innermost of Neptune's moons

100 kilometres

The Suez Canal is 163 kilometres long

A length of 100 kilometers (about 62 English miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the FAI defines spaceflight to begin. To help compare orders of magnitude, this section lists lengths between 100 and 1,000 kilometres (10⁵ and 10⁶ metres).

Conversions

A distance of 100 kilometres is equal to about 62 miles (or 62.13711922 miles).

Human-defined scales and structures

• 100 km — the Karman line: the official boundary of outer space
• 105 km — distance from Giridih to Bokaro
• 109 km — length of High Speed 1 between London and the Channel Tunnel^[116]
• 130 km — range of a Scud-A missile
• 163 km — length of the Suez Canal
• 164 km — length of the Danyang–Kunshan Grand Bridge
• 213 km — length of Paris Métro
• 217 km — length of the Grand Union Canal
• 223 km — length of the Madrid Metro
• 300 km — range of a Scud-B missile
• 386 km — altitude of the International Space Station
• 408 km — length of the London Underground (active track)
• 460 km — distance from London to Paris
• 470 km — distance from Dublin to London as the crow flies
• 600 km — range of a Scud-C missile
• 600 km — height above ground of the Hubble Space Telescope
• 804.67 km — (500 miles) distance of the Indy 500 automobile race

Geographical

• 111 km — distance covered by one degree of latitude on Earth's surface
• 180 km — distance between Mumbai and Nashik
• 203 km — length of Sognefjorden, the third largest fjord in the world
• 220 km — distance between Pune and Nashik
• 240 km — widest width of the English Channel
• 430 km — length of the Pyrenees
• 500 km — widest width of Sweden from east to west
• 550 km — distance from San Francisco to Los Angeles as the crow flies
• 560 km — distance of Bordeaux–Paris, formerly the longest one-day professional cycling race^[117]
• 590 km — length of land boundary between Finland and Sweden
• 724 km — length of the Om River
• 871 km — distance from Sydney to Melbourne (along the Hume Highway)
• 897 km — length of the River Douro
• 900 km — distance from Berlin to Stockholm
• 956 km - distance from Washington, DC to Chicago, Illinois as the crow flies

Astronomical

• 100 km — the altitude at which the FAI defines spaceflight to begin
• 167 km — diameter of Amalthea, one of Jupiter's inner moons
• 200 km — width of Valles Marineris
• 220 km — diameter of Phoebe, the largest of Saturn's outer moons
• 300 km — the approximate distance travelled by light in one millisecond
• 340 km — diameter of Nereid, the third largest moon of Neptune
• 350 km — lower bound of Low Earth orbit
• 420 km — diameter of Proteus, the second largest moon of Neptune
• 468 km — diameter of the asteroid 4 Vesta
• 472 km — diameter of Miranda, one of Uranus' major moons
• 974.6 km — greatest diameter of 1 Ceres,^[118] the largest solar system asteroid^{[note 2]}

1 megametre

Small planets, the Moon and dwarf planets in our solar system have diameters from one to ten million metres. Top row: Mars (left), Mercury (right); bottom row: Moon (left), Pluto (center), and Haumea (right), to scale.

To help compare different orders of magnitude this section lists lengths starting at 10⁶ m (1 Mm or 1,000 km).

Conversions

1 megametre is equal to:

• 1 E+6 m (one million metres)
• approximately 621.37 miles
• Side of square with area 1,000,000 km²

Human-defined scales and structures

• 1.000 Mm – Length of 1 megameter
• 2.100 Mm – Length of proposed gas pipeline from Iran to India via Pakistan
• 2.100 Mm – Distance from Casablanca to Rome
• 2.288 Mm – Length of the official Alaska Highway when it was built in the 1940s^[119]
• 3.069 Mm – Length of Interstate 95 (from Houlton, Maine to Miami, Florida)
• 3.846 Mm – Length of U.S. Route 1 (from Fort Kent, Maine to Key West, Florida)
• 5.000 Mm – Width of the United States
• 5.007 Mm – Estimated length of Interstate 90 (Seattle, Washington to Boston, Massachusetts)
• 5.614 Mm – Length of the Australian Dingo Fence^[120]
• 6.4 Mm – Length of the Great Wall of China
• 7.821 Mm – Length of the Trans-Canada Highway, the world's longest national highway (from Victoria, British Columbia to St. John's, Newfoundland)
• 8.836 Mm – Road distance between Prudhoe Bay, Alaska, and Key West, Florida, the endpoints of the U.S. road network
• 8.852 Mm – Aggregate length of the Great Wall of China, including trenches, hills and rivers^[121]
• 9.259 Mm – Length of the Trans-Siberian railway^[122]

Sports

• The Munda Biddi Trail in WA, Australia is over 1000 km long - the world's longest off-road cycle trail
• 1.200 Mm – the length of the Paris–Brest–Paris bicycling event
• Several endurance auto races are, or were, run for 1,000 km:
  • Bathurst 1000
  • 1000 km Brands Hatch
  • 1000 km Buenos Aires
  • 1000 km Donington
  • 1000 km Monza
  • 1000 km Nürburgring
  • 1000 km Silverstone
  • 1000 km Spa
  • 1000 km Suzuka
  • 1000 km Zeltweg

Geographical

• 1.010 Mm – Distance from San Diego to El Paso as the crow flies
• 2.000 Mm – Distance from Beijing to Hong Kong as the crow flies
• 2.800 Mm – Narrowest width of Atlantic Ocean (Brazil-West Africa)
• 2.850 Mm – Length of the Danube river
• 2.205 Mm – Length of Sweden's total land boundaries
• 2.515 Mm – Length of Norway's total land boundaries
• 3.690 Mm – Length of the Volga river, longest in Europe
• 4.350 Mm – Length of the Yellow River
• 4.715 Mm – Length of the Nile
• 4.800 Mm – Widest width of Atlantic Ocean (U.S.-Northern Africa)
• 5.100 Mm – Distance from Dublin to New York as the crow flies
• 6.270 Mm – Length of the Mississippi-Missouri River system
• 6.380 Mm – Length of the Yangtze River
• 6.762 Mm – Length of the Amazon system, longest on Earth
• 8.200 Mm – Distance from Dublin to San Francisco as the crow flies

Astronomical

• 1.000 Mm – Estimated shortest axis of triaxial dwarf planet Haumea
• 1.186 Mm – Diameter of Charon, the largest moon of Pluto
• 1.280 Mm – Diameter of the trans-Neptunian object 50000 Quaoar
• 1.436 Mm – Diameter of Iapetus, one of Saturn's major moons
• 1.578 Mm – Diameter of Titania, the largest of Uranus' moons
• 1.960 Mm – Estimated longest axis of Haumea
• 2.326 Mm – Diameter of the dwarf planet Eris, the largest trans-Neptunian object found to date
• 2.374 Mm – Diameter of Pluto
• 2.707 Mm – Diameter of Triton, largest moon of Neptune
• 3.122 Mm – Diameter of Europa, the smallest Galilean satellite of Jupiter
• 3.476 Mm – Diameter of Earth's Moon
• 3.643 Mm – Diameter of Io, a moon of Jupiter
• 4.821 Mm – Diameter of Callisto, a moon of Jupiter
• 4.879 Mm – Diameter of Mercury
• 5.150 Mm – Diameter of Titan, the largest moon of Saturn
• 5.262 Mm – Diameter of Jupiter's moon Ganymede, the largest moon in the solar system
• 6.366 Mm – Radius of Earth
• 6.792 Mm – Diameter of Mars

10 megametres

Planets from Venus up to Uranus have diameters from ten to one hundred million metres. Top row: Uranus (left), Neptune (right); middle row: Earth (left), Sirius B (center), and Venus (right), to scale.

To help compare different orders of magnitude, this section lists lengths starting at 10⁷ metres (10 megametres or 10,000 kilometres).

Conversions

10 megametres (10 Mm) is

• 6,215 miles.
• side of a square of area 100,000,000 square kilometres (km²)
• radius of a circle of area 314,159,265 km²

Human-defined scales and structures

• 11.085 Mm – Length of the Kiev-Vladivostok railway, a longer variant of the Trans-Siberian railway^[123]
• 13.300 Mm – Length of roads being rehabilitated and widened under the National Highway Development Project (launched in 1998) in India
• 39.000 Mm – Length of the SEA-ME-WE 3 optical submarine telecommunications cable, joining 39 points between Norden, Germany and Okinawa, Japan
• 67.000 Mm – Total length of National Highways in India

Geographical

• 10 Mm – Approximate altitude of the outer boundary of the exosphere
• 10.001 Mm – Length of the meridian arc from the North Pole to the Equator (the original definition of the metre was based on this length).
• 60.000 Mm – Total length of the mid-ocean ridges

Astronomical

• 12.000 Mm – Diameter of Sirius B, a white dwarf^[124]
• 12.104 Mm – Diameter of Venus
• 12.742 Mm – Diameter of Earth
• 12.900 Mm – Minimum distance of the meteoroid 2004 FU162 from the center of Earth on 31 March 2004, closest on record
• 14.000 Mm – Smallest diameter of Jupiter's Great Red Spot
• 19.000 Mm – Separation between Pluto and Charon
• 34.770 Mm – Minimum distance of the asteroid 99942 Apophis on 13 April 2029 from the center of Earth
• 35.786 Mm – Altitude of geostationary orbit
• 40.005 Mm – Polar circumference of the Earth
• 40.077 Mm – Equatorial circumference of the Earth
• 49.528 Mm – Diameter of Neptune
• 51.118 Mm – Diameter of Uranus

100 megametres

The Earth-Moon orbit, Saturn, OGLE-TR-122b, Jupiter, and other objects, to scale. Click on image for detailed view and links to other length scales.

To help compare different orders of magnitude, this section lists lengths starting at 10⁸ metres (100 megametres or 100,000 kilometres or 62,150 miles).

• 102 Mm – Diameter of HD 149026 b, an unusually dense Jovian planet
• 111.191 Mm – 20,000 (nautical, British) leagues (see Jules Verne, Twenty Thousand Leagues Under the Sea)
• 115 Mm – Width of Saturn's Rings
• 174 Mm – Diameter of 2MASS J0528-1403, the smallest known star
• 120 Mm – Diameter of Saturn
• 142 Mm – Diameter of Jupiter, the largest planet in the solar system
• 170 Mm – Diameter of TRAPPIST-1, a star recently discovered to have 7 planets around it
• 174 Mm – Diameter of OGLE-TR-122b
• 180 Mm – Average distance covered during life
• 196 Mm – Diameter of Proxima Centauri, a typical red dwarf
• 242 Mm – Diameter of WASP-12b
• 250 Mm – Diameter of TrES-4
• 299.792 Mm – One light second; the distance light travels in vacuum in one second (see speed of light)
• 300 Mm – Diameter of WASP-17b
• 307 Mm – Diameter of CT Cha b
• 384.4 Mm (238,855 mi) – Average Earth-Moon distance^[125]
• 671 Mm – Separation between Jupiter and Europa
• 964 Mm – Diameter of HD 100546 b, the largest known planet

1 gigametre

Upper part: Gamma Orionis, Algol B, the Sun (centre), underneath their darker mirror images (artist's interpretation), and other objects, to scale.

To help compare different distances this section lists lengths starting at 10⁹ metres (1 gigametre (Gm) or 1 billion metres).

• 1.2 Gm – Separation between Saturn and Titan
• 1.39 Gm – Diameter of Sun^[126]
• 1.5 Gm – (proposed) Expected orbit from Earth of the James Webb Space Telescope
• 2.19 Gm – Closest approach of Comet Lexell to Earth, happened on 1 July 1770; closest comet approach on record
• 3 Gm – Total length of "wiring" in the human brain.^[127]
• 4.2 Gm – Diameter of Algol B
• 5.0 Gm – Closest approach of Comet Halley to Earth, happened on 10 April 837
• 5.0 Gm – (proposed) Size of the arms of the giant triangle shaped Michelson interferometer of the Laser Interferometer Space Antenna (LISA) planned to start observations in or around 2015.
• 7.9 Gm – Diameter of Gamma Orionis
• 9.0 Gm – Estimated diameter of the event horizon of Sagittarius A*, the supermassive black hole in the center of the Milky Way galaxy

10 gigametres

Rigel and Aldebaran (top left and right) compared to smaller stars, the Sun (very small dot in lower middle, with orbit of mercury as yellow ellipse) and transparent sphere with radius of one light minute: click image for larger view and links to other scales.

To help compare different distances this section lists lengths starting at 10¹⁰ metres (10 gigametres (Gm) or 10 million kilometres, or 0.07 Astronomical units).

• 15 Gm – Closest distance of Comet Hyakutake from Earth
• 18 Gm – One light-minute (see yellow sphere in right-hand diagram)
• 24 Gm – Radius of a heliostationary orbit
• 46 Gm – Perihelion distance of Mercury (yellow ellipse on the right)
• 55 Gm – 60,000-year perigee of Mars (last achieved on 27 August 2003)
• 55 Gm - Diameter of Rigel, a blue supergiant star (largest star on right)^[128]
• 58 Gm – Average passing distance between Earth and Mars at the moment they overtake each other in their orbits
• 61 Gm^[129][130] – Diameter of Aldebaran, an orange giant star (large star on right)
• 70 Gm – Aphelion distance of Mercury
• 76 Gm – Neso's apocentric distance; greatest distance of a natural satellite from its parent planet (Neptune)

100 gigametres

From largest to smallest: Jupiter's orbit, red supergiant star Betelgeuse, Mars' orbit, Earth's orbit, star R Doradus, and orbits of Venus, Mercury. Inside R Doradus' depiction are the blue giant star Rigel and red giant star Aldebaran. The faint yellow glow around the Sun represents one light minute. Click image to see more details and links to their scales.

To help compare distances at different orders of magnitude this section lists lengths starting at 10¹¹ metres (100 Gm or 100 million kilometres or 0.7 astronomical units).

• 109 Gm – 0.7 AU – Distance between Venus and the Sun
• 149.6 Gm (93.0 million mi) – 1.0 AU – Distance between the Earth and the Sun - the definition of the astronomical unit
• 180 Gm – 1.2 AU – Maximum diameter of Sagittarius A*, the supermassive black hole in the center of Milky Way galaxy
• 228 Gm – 1.5 AU – Distance between Mars and the Sun
• 570 Gm – 3.8 AU – Length of the tail of Comet Hyakutake measured by Ulysses; the actual value could be much higher
• 591 Gm – 4.0 AU – Minimum distance between the Earth and Jupiter
• 780 Gm – 5.2 AU – Distance between Jupiter and the Sun
• 965 Gm – 6.4 AU – Maximum distance between the Earth and Jupiter

1 terametre

8 things in the Terameter group

Comparison of size of the Kuiper belt (large faint torus) with the star VY Canis Majoris (at its previous estimate, within Saturn's orbit), Betelgeuse (inside Jupiter's orbit) and R Doradus (small central red sphere) together with the orbits of Neptune and Uranus, to scale. The yellow ellipses represent the orbits of each planet and the dwarf planet Pluto.

To help compare different distances, this section lists lengths starting at 10¹² m (1 Tm or 1 billion km or 6.7 astronomical units).

• 1.079 Tm – 7.2 AU – One light-hour
• 1.23 Tm – 8.2 AU – Diameter of Antares
• 1.4 Tm – 9.5 AU – Distance between Saturn and the Sun
• 1.98 Tm – 13.2 AU – Revised estimated diameter of VY Canis Majoris. The newly improved measurement was 30% lower than the previous 2007 estimate.^[131]
• 2.0 Tm – 13.4 AU – Diameter of one of the largest known stars, KY Cygni
• 2.4 Tm – 15.9 AU – Estimated diameter of UY Scuti, the largest known star as of 2013
• 2.9 Tm – 19.4 AU – Previous estimated diameter of VY Canis Majoris, as of 2007.^[132] The size was revised in 2012 through improved measurement techniques. (see above)^[131]
• 2.9 Tm – 19.4 AU – Distance between Uranus and the Sun
• 4.4 Tm – 29.4 AU – Perihelion distance of Pluto
• 4.5 Tm – 30.1 AU – Distance between Neptune and the Sun
• 4.5 Tm – 30.1 AU – Inner radius of the Kuiper belt
• 5.7 Tm – 38.1 AU – Perihelion distance of Eris
• 7.3 Tm – 48.8 AU – Aphelion distance of Pluto
• 7.5 Tm – 50.1 AU – Outer radius of the Kuiper Belt, inner boundary of the Oort Cloud

10 terametres

Sedna's orbit (left) is longer than 100 Tm, but other lengths are between 10 and 100 Tm: Comet Hale-Bopp's orbit (lower, faint orange); one light-day (yellow spherical shell with yellow Vernal point arrow as radius); the heliosphere's termination shock (blue shell); and other arrows show positions of Voyager 1 (red) and Pioneer 10 (green). Click on image for larger view and links to other scales.

To help compare different distances this section lists lengths starting at 10¹³ m (10 Tm or 10 billion km or 67 astronomical units).

• 11.1 Tm – 74.2 AU – Distance that Voyager 1 began detecting returning particles from termination shock
• 11.4 Tm – 76.2 AU – Perihelion distance of 90377 Sedna
• 12.1 Tm – 70 to 90 AU – Distance to termination shock (Voyager 1 crossed at 94 AU)
• 12.9 Tm – 86.3 AU – Distance to 90377 Sedna in March 2014
• 13.2 Tm – 88.6 AU – Distance to Pioneer 11 in March 2014
• 14.1 Tm – 94.3 AU – Estimated radius of the solar system
• 14.4 Tm – 96.4 AU – Distance to Eris in March 2014 (now near its aphelion)
• 15.1 Tm – 101 AU – Distance to heliosheath
• 16.5 Tm – 111 AU – Distance to Pioneer 10 as of March 2014
• 16.6 Tm - 111.2AU - Distance to Voyager 2 as of May 2016
• 20.0 Tm - 135 AU - Distance to Voyager 1 as of May 2016
• 20.6 Tm – 138 AU - Distance to Voyager 1 as of today (late February 2017)
• 25.9 Tm – 172 AU – One light-day
• 55.7 Tm – 371 AU – Aphelion distance of the comet Hale-Bopp

100 terametres

The largest yellow sphere indicates one light month distance from the Sun. Click the image for larger view, more details and links to other scales.

To help compare different distances this section lists lengths starting at 10¹⁴ m (100 Tm or 100,000 million km or 670 astronomical units).

• 146 Tm – 975 AU – Aphelion distance of 90377 Sedna
• 172 Tm – 1150 AU – Schwarzschild diameter of H1821+643, one of the most massive black holes known
• 181 Tm – 1210 AU – One light-week
• 653 Tm – 4367 AU – Aphelion distance of comet Hyakutake (current orbit)^[133]
• 757 Tm – 5059 AU – radius of the Stingray Nebula^[134]
• 777 Tm – 5180 AU – One light-month

1 petametre

Largest circle with yellow arrow indicates one light year from Sun; Cat's Eye Nebula on left and Barnard 68 in middle are depicted in front of Comet 1910 A1's orbit. Click image for larger view, details and links to other scales.

To help compare different distances this section lists lengths starting at 10¹⁵ m (1 Pm or 1,000,000 million km or 6685 astronomical units (AU) or 0.11 light years).

• 1.0 Pm = 0.105702341 light years ^[135]
• 1.9 Pm ± .5 Pm = 12,000 AU = 0.2 light year radius of Cat's Eye Nebula's inner core^[136]
• 4.7 Pm = 30,000 AU = half light year diameter of Bok globule Barnard 68^[137]
• 7.5 Pm – 50,000 AU – Possible outer boundary of Oort cloud (other estimates are 75,000 to 125,000 or even 189,000 AU (1.6, 2, and 3 light years, respectively))
• 7.7 Pm – 52,000 AU – Aphelion distance of the Great Daylight Comet of 1910
• 9.5 Pm – 63,241.1 AU – One light year, the distance travelled by light in one year

10 petametres

Objects with size order of magnitude 1e16m: Ten light years (94.6 Pm) radius circle with yellow Vernal Point arrow; Bubble Nebula (NGC 7635), left; Dumbbell Nebula (NGC 6853), right; one light year shell lower right with the smaller Cat's Eye Nebula (NGC_6543) and Barnard 68 adjacent.

1e16m lengths: Ten light years (94.6 Pm) yellow shell; Sirius below right; BL Ceti below left; Proxima and Alpha Centauri upper right; light year shell with Comet 1910 A1's orbit inside top right

To help compare different distances this section lists lengths starting at 10¹⁶ m (10 Pm or 66,800 AU, 1.06 light years).

• 15 Pm – 1.59 light years – Possible outer radius of Oort cloud
• 20 Pm – 2.11 light years – maximum extent of influence of the Sun's gravitational field
• 30.9 Pm – 3.26 light years – 1 parsec
• 39.9 Pm – 4.22 light years – Distance to Proxima Centauri (nearest star to Sun)
• 81.3 Pm – 8.59 light years – Distance to Sirius

100 petametres

Lengths with order of magnitude 1e17m: yellow Vernal Point arrow traces hundred light year radius circle with smaller ten light year circle at right; globular cluster Messier 5 in background; 12 light year radius Orion Nebula middle right; 50 light year wide view of the Carina Nebula bottom left; Pleiades cluster and Bubble nebula with similar diameters each around 10 light years bottom right; grey arrows show distances from Sun to stars Aldebaran (65 light years) and Vega (25 light years).

To help compare different distances this section lists lengths between 10¹⁷ m (100 Pm or 11 light years) and 10¹⁸ m (106 light years).

• 110 Pm – 12 light years – Distance to Tau Ceti
• 230 Pm – 24 light years – Diameter of the Orion Nebula^[138][139]
• 240 Pm – 25 light years – Distance to Vega
• 260 Pm – 27 light years – Distance to Chara, a star approximately as bright as our Sun. Its faintness gives us an idea how our Sun would appear when viewed from even so close a distance as this.
• 350 Pm – 37 light years – Distance to Arcturus
• 373.1 Pm – 39.44 light years - Distance to TRAPPIST-1, a star recently discovered to have 7 planets around it.
• 400 Pm – 42 light years – Distance to Capella
• 620 Pm – 65 light years – Distance to Aldebaran

1 exametre

Lengths with order of magnitude 1e18m: thousand light year radius circle with yellow arrow and 100 light year circle at right with globular cluster Messier 5 within and Carina Nebula in front; globular cluster Omega Centauri to left of both; part of the 1400 light year wide Tarantula Nebula fills the background.

This list includes distances between 1 and 10 exametres (10¹⁸ m). To help compare different distances this section lists lengths between 10¹⁸ m (1 Em or 105.7 light years) and 10¹⁹ m (1057 light years).

• 1.2 Em – 129 light years – Diameter of Messier 13 (a typical globular cluster)
• 1.6 Em – 172 ± 12.5 light years – Diameter of Omega Centauri (one of the largest known globular clusters, perhaps containing over a million stars)^[140][141]
• 3.1 Em – 310 light years – Distance to Canopus according to Hipparcos^[142]
• 6.1 Em – 640 light years – Distance to Betelgeuse according to Hipparcos^[143]
• 9 Em – 600 light years – Diameter of the Tarantula Nebula
• 6.2 Em – 650 light years – Distance to the Helix Nebula, located in the constellation Aquarius^[144]
• 7.3 Em – 730 light years – Distance to Rigel according to Hipparcos^[142]

10 exametres

To help compare different orders of magnitude, this section lists distances starting at 10 Em (10¹⁹ m or 1,100 light years).

• 13 Em – 1,300 light years – Distance to the Orion Nebula^[145]
• 14 Em – 1,500 light years – Approximate thickness of the plane of the Milky Way galaxy at the Sun's location
• 14.2 Em – 1,520 light years – Diameter of the NGC 604
• 30.8568 Em – 3,261.6 light years – 1 kiloparsec
• 31 Em – 3,200 light years – Distance to Deneb according to Hipparcos
• 46 Em – 4,900 light years – Distance to OGLE-TR-56, the first extrasolar planet discovered using the transit method
• 47 Em – 5,000 light years – Distance to the Boomerang nebula, coldest place known (1 K)
• 53 Em – 5,600 light years – Distance to the globular cluster M4 and the extrasolar planet PSR B1620-26 b within it
• 61 Em – 6,500 light years – Distance to Perseus Spiral Arm (next spiral arm out in the Milky Way galaxy)
• 71 Em – 7,500 light years – Distance to Eta Carinae

100 exametres

To help compare different orders of magnitude, this section lists distances starting at 100 Em (10²⁰ m or 11,000 light years).

• 150 Em – 16,000 light years – Diameter of the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way
• 200 Em – 21,500 light years – Distance to OGLE-2005-BLG-390Lb, the most distant and the most Earth-like planet known
• 240 Em – 25,000 light years – Distance to the Canis Major Dwarf Galaxy
• 260 Em – 28,000 light years – Distance to the center of the Galaxy
• 830 Em – 88,000 light years – Distance to the Sagittarius Dwarf Elliptical Galaxy
• >950 Em – >100,000 light years – Diameter of the disc of the Milky Way Galaxy

1 zettametre

The zettametre (SI symbol: Zm) is a unit of length in the metric system equal to 10²¹ metres.^[146]

To help compare different orders of magnitude, this section lists distances starting at 1 Zm (10²¹ m or 110,000 light years).

• 1.7 Zm – 179,000 light years – Distance to the Large Magellanic Cloud, largest satellite galaxy of the Milky Way
• 2.0 Zm – 210,000 light years – Distance to the Small Magellanic Cloud
• 2.8 Zm – 300,000 light years – Distance to the Intergalactic Wanderer, one of the most distant globular clusters of Milky Way
• 8.5 Zm – 900,000 light years – Distance to the Leo I Dwarf Galaxy, farthest known Milky Way satellite galaxy

10 zettametres

To help compare different orders of magnitude, this section lists distances starting at 10 Zm (10²² m or 1.1 million light years).

• 24 Zm – 2.5 million light years – Distance to the Andromeda Galaxy^[147]
• 30.8568 Zm – 3.2616 million light years – 1 megaparsec
• 40 Zm – 4.2 million light years – Distance to the IC 10, a distant member of the Local Group of galaxies
• 49.2 Zm – 5.2 million light years – Width of the Local Group of galaxies
• 57 Zm – 6 million light years – Diameter of the supergiant elliptical galaxy IC 1101
• 95 Zm – 10 million light years – Distance to the Sculptor Galaxy in the Sculptor Group of galaxies
• 95 Zm – 10 million light years – Distance to the Maffei 1, the nearest giant elliptical galaxy in the Maffei 1 Group

100 zettametres

To help compare different orders of magnitude, this section lists distances starting at 100 Zm (10²³ m or 11 million light years).

• 140 Zm – 15 million light years – Distance to Centaurus A galaxy
• 250 Zm – 27 million light years – Distance to the Pinwheel Galaxy
• 280 Zm – 30 million light years – Distance to the Sombrero Galaxy
• 570 Zm – 60 million light years – Approximate distance to the Virgo cluster, nearest galaxy cluster
• 620 Zm – 65 million light years – Approximate distance to the Fornax cluster
• 800 Zm – 85 million light years – Approximate distance to the Eridanus cluster

1 yottametre

The yottametre or yottameter in the US ( SI symbol: Ym) is a unit of length in the metric system equal to 10²⁴ metres^[146]

To help compare different orders of magnitude, this section lists distances starting at 1 Ym (10²⁴ m or 105.702 million light years).

• 1.2 Ym – 127 million light years – Distance to the closest observed gamma ray burst GRB 980425
• 1.3 Ym – 137 million light years – Distance to the Centaurus Cluster of galaxies, the nearest large supercluster
• 1.9 Ym – 201 million light years – Diameter of the Local Supercluster
• 2.3 Ym – 225 to 250 million light years – Distance light travels in vacuum in one galactic year
• 2.8 Ym – 296 million light years – Distance to the Coma Cluster
• 3.2 Ym – 338 million light years – Distance to the Stephan's Quintet
• 4.7 Ym – 496 million light years – Length of the CfA2 Great Wall, one of the largest observed superstructures in the Universe
• 6.1 Ym – 645 million light years – Distance to the Shapley Supercluster
• 9.5 Ym – 996 million light years – Diameter of the Eridanus Supervoid

10 yottametres

The universe within 1 billion light years of Earth

To help compare different orders of magnitude, this section lists distances starting at 10 Ym (10²⁵ m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the cosmological models used.

• 13.7 Ym – 1.37 billion light-years – Length of the Sloan Great Wall
• 18 Ym – redshift 0.16 – 1.9 billion light-years – Distance to the quasar 3C 273 (light travel distance)
• 33 Ym – 3.5 billion light-years – Maximum distance of the 2dF Galaxy Redshift Survey (light travel distance)
• 37.8 Ym – 4 billion light-years – Length of the Huge-LQG
• 75 Ym – redshift 0.95 – 8 billion light-years – Approximate distance to the supernova SN 2002dd in the Hubble Deep Field North (light travel distance)
• 85 Ym – redshift 1.6 – 9 billion light-years – Approximate distance to the gamma ray burst GRB 990123 (light travel distance)
• 94.6 Ym – 10 billion light-years – Approximate distance to quasar OQ172
• 94.6 Ym – 10 billion light-years – Length of the Hercules-Corona Borealis Great Wall, one of the largest and most massive known cosmic structure.

100 yottametres

To help compare different orders of magnitude, this section lists distances starting at 100 Ym (10²⁶ m or 11 billion light years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.

Distances longer than 100 Ym

• 130 Ym – redshift 6.41 – 13 billion light years – Light travel distance (LTD) to the quasar SDSS J1148+5251
• 130 Ym – redshift 1000 – 13.8 billion light years – Distance (LTD) to the source of the cosmic microwave background radiation; radius of the observable universe measured as a LTD
• 260 Ym – 27.4 billion light years – Diameter of the observable universe (double LTD)
• 440 Ym – 46 billion light years – Radius of the universe measured as a comoving distance.
• 590 Ym – 62 billion light years – Cosmological event horizon: the largest comoving distance from which light will ever reach us (the observer) at any time in the future
• 886.48 Ym – 93.7 billion light years – The diameter of the observable universe; however, there might be unobserved distances that are even greater.
• >1,000 Ym (1 kYm or xennameter in older usage) – Size of universe beyond the cosmic light horizon, depending on its curvature; if the curvature is zero (i.e. the universe is spatially flat), the value can be infinite (see shape of the universe) as previously mentioned

Notes

References

External links

• How Big Are Things? displays orders of magnitude in successively larger rooms
• Powers of Ten Travel across the Universe. Altering perspective by changing scale by just a few powers of ten (interactive)
• Cosmos – an Illustrated Dimensional Journey from microcosmos to macrocosmos – from Digital Nature Agency
• Scale of the universe- interactive guide to length magnitudes