Location of Earth
Knowledge of the location of Earth has been shaped by 400 years of telescopic observations, and has expanded radically since the start of the 20th century. Initially, Earth was believed to be the center of the Universe, which consisted only of those planets visible with the
megaparsecs[a]) the Universe becomes homogeneous, meaning that all its parts have on average the same density, composition and structure.[7]
Since there is believed to be no "center" or "edge" of the Universe, there is no particular reference point with which to plot the overall location of the Earth in the universe.
Details
Earth is the third planet from the Sun with an approximate distance of 149.6 million kilometres (93.0 million miles), and is traveling nearly 2.1 million kilometres per hour (1.3 million miles per hour) through outer space.[11]
Table
Feature | Diameter | Notes | Sources | ||
---|---|---|---|---|---|
(most suitable unit) | (km, with scientific notation) | (km, as a power of 10, Logarithmic scale) | |||
Earth | 12,756.2 km (equatorial) |
1.28×104 | 4.11 | Measurement comprises just the solid part of the Earth; there is no agreed upper boundary for Earth's atmosphere. The geocorona, a layer of UV-luminescent hydrogen atoms, lies at 100,000 km. The Kármán line, defined as the boundary of space for astronautics, lies at 100 km. |
[12][13][14][15] |
Orbit of the Moon | 768,210 km[b] | 7.68×105 | 5.89 | The average diameter of the orbit of the Moon relative to the Earth. | [16] |
Geospace |
6,363,000–12,663,000 km (110–210 Earth radii) |
6.36×106–1.27×107 | 6.80–7.10 | The space dominated by magnetotail, shaped by the solar wind . |
[17] |
Earth's orbit | 299.2 million km[b] 2 AU[c] |
2.99×108 | 8.48 | The average diameter of the orbit of the Earth relative to the Sun. Encompasses the Sun, Mercury and Venus. |
[18] |
Inner Solar System |
~6.54 AU | 9.78×108 | 8.99 | Encompasses the Sun, the inner planets (Mercury, Venus, Earth, Mars) and the asteroid belt. with Jupiter, which marks the outer limit of the asteroid belt.Cited distance is the 2:1 resonance |
[19][20][21] |
Outer Solar System |
60.14 AU | 9.00×109 | 9.95 | Includes the ). Cited distance is the orbital diameter of Neptune. |
[22] |
Kuiper belt | ~96 AU | 1.44×1010 | 10.16 | Belt of icy objects surrounding the Makemake. with Neptune, generally regarded as the outer edge of the main Kuiper belt.Cited distance is the 2:1 resonance |
[23] |
Heliosphere | 160 AU | 2.39×1010 | 10.38 | Maximum extent of the solar wind and the interplanetary medium. | [24][25] |
Scattered disc | 195.3 AU | 2.92×1010 | 10.47 | Region of sparsely scattered icy objects surrounding the Kuiper belt. Encompasses the dwarf planet aphelion of Eris, the farthest known scattered disc object.As of now, Eris's aphelion marks the farthest known point in the scattered disc. |
[26] |
Oort cloud | 100,000–200,000 AU 0.613–1.23 pc[a] |
1.89×1013–3.80×1013 | 13.28–13.58 | Spherical shell of over a trillion (1012) long-period comets . |
[27] |
Solar System | 1.23 pc | 3.80×1013 | 13.58 | The Sun and its planetary system. Cited diameter is that of the Sun's Hill sphere; the region of its gravitational influence. | [28] |
Local Interstellar Cloud | 9.2 pc | 2.84×1014 | 14.45 | Interstellar cloud of gas through which the Sun and a number of other stars are currently travelling. | [29] |
Local Bubble | 2.82–250 pc | 8.70×1013–7.71×1015 | 13.94–15.89 | Cavity in the interstellar medium in which the Sun and a number of other stars are currently travelling. Caused by a past supernova. |
[30][31] |
Gould Belt | 1,000 pc | 3.09×1016 | 16.49 | Projection effect of the Radcliffe wave and Split linear structures (Gould Belt),[32] between which the Sun is currently travelling. | [33] |
Orion Arm | 3000 pc (length) |
9.26×1016 | 16.97 | The spiral arm of the Milky Way Galaxy through which the Sun is currently travelling. |
|
Orbit of the Solar System | 17,200 pc | 5.31×1017 | 17.72 | The average diameter of the orbit of the Solar System relative to the Galactic Center. The Sun's orbital radius is roughly 8,600 parsecs, or slightly over half way to the galactic edge. One orbital period of the Solar System lasts between 225 and 250 million years. |
[34][35] |
Milky Way Galaxy |
30,000 pc | 9.26×1017 | 17.97 | Our home galaxy, composed of 200 billion to 400 billion stars and filled with the interstellar medium. | [36][37] |
Milky Way subgroup |
840,500 pc | 2.59×1019 | 19.41 | The Milky Way and those satellite Leo T Dwarf galaxy, the most distant galaxy in the Milky Way subgroup. Currently 59 satellite galaxies are part of the subgroup. |
[38] |
Local Group | 3 Mpc[a]
|
9.26×1019 | 19.97 | dwarf galaxies . |
[39] |
Local Sheet | 7 Mpc | 2.16×1020 | 20.33 | Group of galaxies including the Local Group moving at the same relative velocity towards the Virgo Cluster and away from the Local Void. | [40][41] |
Virgo Supercluster | 30 Mpc | 9.26×1020 | 20.97 | The supercluster of which the Local Group is a part. It comprises roughly 100 galaxy groups and clusters, centred on the Virgo Cluster. The Local Group is located on the outer edge of the Virgo Supercluster. |
[42][43] |
Laniakea Supercluster | 160 Mpc | 4.94×1021 | 21.69 | A group connected with the superclusters of which the Local Group is a part. Comprises roughly 300 to 500 galaxy groups and clusters, centred on the Great Attractor in the Hydra–Centaurus Supercluster. |
[44][45][46][47] |
Pisces–Cetus Supercluster Complex | 330 Mpc | 1×1022 | 21.98 | Sculptor Supercluster and associated smaller filamentary chains. |
[48][49] |
Observable Universe | 28,500 Mpc | 8.79×1023 | 23.94 | foam-like superstructure . |
[50][51][52][53] |
Universe | Minimum 28,500 Mpc (possibly infinite) |
Minimum 8.79×1023 | Minimum 23.94 | Beyond the observable universe lie the unobservable regions from which no light has yet reached the Earth. No information is available, as light is the fastest travelling medium of information. However, uniformitarianism argues that the Universe is likely to contain more galaxies in the same foam-like superstructure. |
[54] |
Gallery
Location of Earth in the
Observable Universe of the Universe
See also
Notes
- ^ megaparsec (Mpc) is equivalent to one million parsecs.
- ^ semi-minor axes.
- ^ 1 AU or astronomical unit is the distance between the Earth and the Sun, or 150 million km. Earth's orbital diameter is twice its orbital radius, or 2 AU.
References
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