Timeline of the early universe

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The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang (13.799 ± 0.021 billion years ago) to the present day. An epoch is a moment in time from which nature or situations change to such a degree that it marks the beginning of a new era or age.

Times on this list are measured from the moment of the Big Bang.

The first 20 minutes

Planck epoch

• c. 0 seconds (13.799 ± 0.021
  WIMPS (weakly interacting massive particles) or dark matter and dark energy
  may have appeared and been the catalyst for the expansion of the singularity. The infant universe cools as it begins expanding outward. It is almost completely smooth, with quantum variations beginning to cause slight variations in density.

• c. 10⁻⁴³ seconds:
  electronuclear force, also known as the Grand Unified Force or Grand Unified Theory (GUT), mediated by (the hypothetical) X and Y bosons which allow early matter at this stage to fluctuate between baryon and lepton states.^[1]

• c. 10⁻³⁶ seconds:
  Higgs bosons
  .
• c. 10⁻³³ seconds:
  supercooled from about 10²⁷ down to 10²² kelvin.^[2]
• c. 10⁻³² seconds: Cosmic inflation ends. The familiar elementary particles now form as a soup of hot ionized gas called quark–gluon plasma; hypothetical components of cold dark matter (such as axions) would also have formed at this time.

Quark epoch

• c. 10⁻¹² seconds:
  Higgs Field. The temperature is still too high for quarks to coalesce into hadrons, and the quark–gluon plasma persists (Quark epoch
  ). The universe cools to 10¹⁵ kelvin.
• c. 10⁻¹¹ seconds:
  antibaryon
  constituencies are established.

• c. 1 second:
  antiquarks. Gravity governs the expansion of the universe: neutrinos decouple from matter creating a cosmic neutrino background
  .

• c. 10 seconds:
  positrons
  annihilate, a small number of unmatched electrons are left over – disappearance of the positrons.
• c. 10 seconds: Universe dominated by photons of radiation – ordinary matter particles are coupled to light and radiation while dark matter particles start building non-linear structures as dark matter halos. Because charged electrons and protons hinder the emission of light, the universe becomes a super-hot glowing fog.
• c. 3 minutes: Primordial nucleosynthesis: nuclear fusion begins as lithium and heavy hydrogen (deuterium) and helium nuclei form from protons and neutrons.
• c. 20 minutes: Nuclear fusion ceases: normal matter consists by mass of 75% hydrogen nuclei and 25% helium nuclei or one helium nucleus per twelve hydrogen nuclei– free electrons begin scattering light.

Matter era

Matter and radiation equivalence

• c. 47,000 years (z=3600): Matter and radiation equivalence: at the beginning of this era, the expansion of the universe was decelerating at a faster rate.
• c. 70,000 years: Matter domination in Universe: onset of gravitational collapse as the Jeans length at which the smallest structure can form begins to fall.

Cosmic Dark Age

• c. 370,000 years (z=1,100): The "
  atoms, mostly hydrogen and helium. Distributions of hydrogen and helium at this time remains constant as the electron-baryon plasma thins. The temperature falls to 3000 kelvin. Ordinary matter particles decouple from radiation. The photons present at the time of decoupling are the same photons that we see in the cosmic microwave background
  (CMB) radiation.
• c. 400,000 years: Density waves begin imprinting characteristic polarization signals.
• c. 10-17 million years: The "Dark Ages" span a period during which the temperature of
  liquid water, during a period of about 7 million years, from about 10 to 17 million after the Big Bang (redshift 137–100). Loeb (2014) speculated that primitive life might in principle have appeared during this window, which he called "the Habitable Epoch of the Early Universe".^[3][4][5]
• c. 100 million years: Gravitational collapse: ordinary matter particles fall into the structures created by dark matter.
  quasars) begin to take shape – their ultraviolet
  light ionizes remaining neutral gas.
• 200–300 million years: First stars begin to shine: Because many are
  Population II stars are accounted for at this time) they are much bigger and hotter and their life cycle is fairly short. Unlike later generations of stars, these stars are metal free. Reionization begins, with the absorption of certain wavelengths of light by neutral hydrogen creating Gunn–Peterson troughs. The resulting ionized gas (especially free electrons) in the intergalactic medium causes some scattering
  of light, but with much lower opacity than before recombination due the expansion of the universe and clumping of gas into galaxies.
• 200 million years:
  The oldest-known star
  (confirmed) – SMSS J031300.36-670839.3, forms.
• 300 million years: First large-scale astronomical objects,
  gas giants
  .
• 320 million years (z=13.3):
  HD1, the oldest-known spectroscopically-confirmed galaxy, forms.^[7]
• 380 million years: UDFj-39546284 forms, current record holder for unconfirmed oldest-known quasar.^[8]
• 420 million years: The quasar MACS0647-JD, the, or one of the, furthest known quasars, forms.
• 600 million years HE 1523-0901, the oldest star found producing neutron capture elements forms, marking a new point in ability to detect stars with a telescope.^[9]
• 630 million years (z=8.2):
  gamma ray burst recorded suggests that supernovas may have happened very early on in the evolution of the Universe^[10]
• 670 million years:
  starburst galaxies
  are often associated with collisions and galaxy mergers.
• 700 million years: Galaxies form. Smaller galaxies begin merging to form larger ones. Galaxy classes may have also begun forming at this time including
  spiral galaxies). UDFy-38135539, the first distant quasar to be observed from the reionization phase, forms. Dwarf galaxy z8 GND 5296 forms. Galaxy or possible proto-galaxy A1689-zD1
  forms.
• 720 million years: Possible formation of
  globular clusters in Milky Way's Galactic halo. Formation of globular cluster, NGC 6723
  , in the Milky Way's galactic halo
• 740 million years: 47 Tucanae, second-brightest globular cluster in the Milky Way, forms
• 750 million years: Galaxy IOK-1 a Lyman alpha emitter galaxy, forms. GN-108036 forms—galaxy is 5 times larger and 100 times more massive than the present day Milky Way illustrating the size attained by some galaxies very early on.
• 770 million years: Quasar ULAS J1120+0641, one of the most distant, forms. One of the earliest galaxies to feature a supermassive black hole suggesting that such large objects existed quite soon after the Big Bang. The large fraction of neutral hydrogen in its spectrum suggests it may also have just formed or is in the process of star formation.
• 800 million years: Farthest extent of
  Lyman alpha emitter galaxies, forms. Lyman alpha emitters are considered to be the progenitors of spiral galaxies like the Milky Way. Messier 2
  , globular cluster, forms.
• 870 million years:
  Core collapse (cluster)
  , the cluster has one of the highest densities among globular clusters.
• 890 million years: Galaxy SXDF-NB1006-2 forms
• 900 million years: Galaxy BDF-3299 forms.
• 910 million years: Galaxy BDF-521 forms

Galaxy epoch

• 1 billion years (12.8
  galaxy superclusters
  appear.
• 1.1 billion years (12.7 Gya): Age of the
  PSR B1620-26 b forms. It is a gas giant known as the "Genesis Planet" or "Methusaleh." The oldest observed exoplanet in the Universe, it orbits a pulsar and a white dwarf
  .
• 1.13 billion years (12.67 Gya): Messier 12, globular cluster, forms
• 1.3 billion years (12.5 Gya):
  PSR J1719-1438 b
  , known as the Diamond Planet, forms around a pulsar.
• 1.31 billion years (12.49 Gya): Globular Cluster Messier 53 forms 60,000 light-years from the Galactic Center of the Milky Way
• 1.39 billion years (12.41 Gya): S5 0014+81, a hyper-luminous quasar, forms
• 1.4 billion years (12.4 Gya): Age of Cayrel's Star, BPS C531082-0001, a neutron capture star, among the oldest Population II stars in Milky Way. Quasar RD1, first object observed to exceed redshift 5, forms.
• 1.44 billion years (12.36 Gya):
  blue stragglers
  "
• 1.5 billion years (12.3 Gya): Messier 55, globular cluster, forms
• 1.8 billion years (12 Gya): Most energetic gamma ray burst lasting 23 minutes, GRB 080916C, recorded. Baby Boom Galaxy forms. Terzan 5 forms as a small dwarf galaxy on collision course with the Milky Way. Dwarf galaxy carrying the Methusaleh Star consumed by Milky Way – oldest-known star in the Universe becomes one of many population II stars of the Milky Way
• 2.0 billion years (11.8 Gya): SN 1000+0216, the oldest observed supernova occurs – possible pulsar formed. Globular Cluster Messier 15, known to have an intermediate black hole and the only globular cluster observed to include a planetary nebula, Pease 1, forms
• 2.02 billion years (11.78 Gya):
  variable stars (89) many of which are RR Lyrae
  stars.
• 2.2 billion years (11.6 Gya): Globular Cluster NGC 6752, third-brightest, forms in Milky Way
• 2.4 billion years (11.4 Gya): Quasar PKS 2000-330 forms.
• 2.41 billion years (11.39 Gya):
  Oosterhoff type I
  cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements.
• 2.5 billion years (11.3 Gya): Omega Centauri, largest globular cluster in the Milky Way forms
• 2.6 billion years (11.2 Gya): HD 130322 planetary system, known as the first observed exoplanet system, forms
• 3.0 billion years (10.8 billion Gya): Formation of the
  habitable planets
  , form. Gliese 581d has more potential for forming life since it is the first exoplanet of terrestrial mass proposed that orbits within the habitable zone of its parent star.
• 3.3 billion years (10.5 Gya): BX442, oldest grand design spiral galaxy observed, forms
• 3.5 billion years (10.3 Gya): Supernova SN UDS10Wil recorded
• 3.8 billion years (10 Gya): NGC 2808 globular cluster forms: 3 generations of stars form within the first 200 million years.
• 4.0 billion years (9.8 Gya): Quasar
  GRB 991216 recorded. Gliese 677 Cc, a planet in the habitable zone of its parent star, Gliese 667
  , forms
• 4.5 billion years (9.3 Gya): Fierce star formation in Andromeda making it into a luminous
  infra-red
  galaxy
• 5.0 billion years (8.8 Gya): Earliest
  asteroids, and icy comets
• 5.1 billion years (8.7 Gya): Galaxy collision: spiral arms of the Milky Way form leading to major period of star formation.
• 5.3 billion years (8.5 Gya):
  Kepler 11 planetary system, the flattest and most compact system yet discovered, forms – Kepler 11 c
  considered to be a giant ocean planet with hydrogen-helium atmosphere.
• 5.8 billion years (8 Gya): 51 Pegasi b also known as Dimidium, forms – first planet discovered orbiting a main sequence star
• 5.9 billion years (7.9 Gya):
  astrometrics
  , forms
• 6.0 billion years (7.8 Gya): Many galaxies like NGC 4565 become relatively stable – ellipticals result from collisions of spirals with some like IC 1101 being extremely massive.
• 6.0 billion years (7.8 Gya): The Universe continues to organize into larger wider structures. The great walls, sheets and filaments consisting of galaxy clusters and superclusters and voids crystallize. How this crystallization takes place is still conjecture. Certainly, it is possible the formation of super-structures like the Hercules–Corona Borealis Great Wall may have happened much earlier, perhaps around the same time galaxies first started appearing. Either way the observable universe becomes more modern looking.
• 6.2 billion years (7.7 Gya):
  trinary star system
  , forms – orbiting moons considered to have habitable properties or at the least capable of supporting water
• 6.3 billion years (7.5 Gya, z=0.94):
  Sagittarius Dwarf Elliptical Galaxy
• 6.5 billion years (7.3 Gya): HD 10180 planetary system forms (larger than both 55 Cancri and Kepler 11 systems)
• 6.9 billion years (6.9 Gya): Orange Giant, Arcturus, forms
• 7.64 billion years (6.16 Gya): Mu Arae planetary system forms: of four planets orbiting a yellow star, Mu Arae c is among the first terrestrial planets to be observed from Earth
• 7.8 billion years (6.0 Gya): Formation of Earth's near twin,
  Kepler 452
• 7.98 billion years (5.82 Gya): Formation of Mira or Omicron ceti, binary star system. Formation of Alpha Centauri Star System, closest star to the Sun. GJ 1214 b, or Gliese 1214 b, potential Earth-like planet, forms
• 8.2 billion years (5.6 Gya): Tau Ceti, nearby yellow star forms: five planets eventually evolve from its planetary nebula, orbiting the star – Tau Ceti e considered planet to have potential life since it orbits the hot inner edge of the star's habitable zone
• 8.5 billion years (5.3 Gya): GRB 101225A, the "Christmas Burst", considered the longest at 28 minutes, recorded

Acceleration

• 8.8 billion years (5 Gya, z=0.5):
  matter-dominated era during which cosmic expansion was slowing down.^[11]
• 8.8 billion years (5 Gya): Messier 67 open star cluster forms: Three exoplanets confirmed orbiting stars in the cluster including a twin of the Sun
• 9.0 billion years (4.8 Gya): Lalande 21185, red dwarf in Ursa Major, forms
• 9.13 billion years (4.67 Gya): Proxima Centauri forms completing the Alpha Centauri trinary system

Epochs of the formation of the Solar System

• 9.2 billion years (4.6–4.57 Gya): Primal supernova, possibly triggers the formation of the Solar System.
• 9.2318 billion years (4.5682 Gya): Sun forms – Planetary nebula begins accretion of planets.
• 9.23283 billion years (4.56717–4.55717 Gya): Four
  Jovian planets (Jupiter, Saturn, Uranus, Neptune
  ) evolve around the Sun.
• 9.257 billion years (4.543–4.5 Gya): Solar System of Eight planets, four terrestrial (Mercury, Venus, Earth, Mars) evolve around the Sun. Because of accretion many smaller planets form orbits around the proto-Sun some with conflicting orbits – Early Heavy Bombardment begins. Precambrian Supereon and Hadean eon begin on Earth. Pre-Noachian Era begins on Mars. Pre-Tolstojan Period begins on Mercury – a large planetoid strikes Mercury stripping it of outer envelope of original crust and mantle, leaving the planet's core exposed – Mercury's iron content is notably high. Many of the Galilean moons may have formed at this time including Europa and Titan which may presently be hospitable to some form of living organism.
• 9.266 billion years (4.533 Gya): Formation of Earth-
  axis of rotation. Pre-Nectarian
  Period begins on Moon
• 9.271 billion years (4.529 Gya): Major collision with a pluto-sized planetoid establishes the Martian dichotomy on Mars – formation of North Polar Basin of Mars
• 9.3 billion years (4.5 Gya): Sun becomes a main sequence yellow star: formation of the
  Hale-Bopp
  begins passing through the Solar System, sometimes colliding with planets and the Sun
• 9.396 billion years (4.404 Gya):
  Liquid water may have existed on the surface of the Earth, probably due to the greenhouse warming of high levels of methane and carbon dioxide
  present in the atmosphere.
• 9.4 billion years (4.4 Gya): Formation of
  Kepler 438 b
  , one of the most Earth-like planets, from a protoplanetary nebula surrounding its parent star
• 9.5 billion years (4.3 Gya): Massive meteorite impact creates South Pole
  Aitken Basin
  on the Moon – a huge chain of mountains located on the lunar southern limb, sometimes called "Leibnitz mountains", form
• 9.6 billion years (4.2 Gya):
  Lunar Maria
• 9.7 billion years (4.1 Gya): Resonance in Jupiter and Saturn's orbits moves Neptune out into the Kuiper belt causing a disruption among asteroids and comets there. As a result,
  Mimas (moon), a moon of Saturn. Meteorite impact creates the Hellas Planitia on Mars, the largest unambiguous structure on the planet. Anseris Mons an isolated massif (mountain
  ) in the southern highlands of Mars, located at the northeastern edge of Hellas Planitia is uplifted in the wake of the meteorite impact
• 9.8 billion years (4 Gya): HD 209458 b, first planet detected through its transit, forms. Messier 85, lenticular galaxy, disrupted by galaxy interaction: complex outer structure of shells and ripples results. Andromeda and Triangulum galaxies experience close encounter – high levels of star formation in Andromeda while Triangulum's outer disc is distorted
• 9.861 billion years (3.938 Gya): Major period of impacts on the Moon: Mare Imbrium forms
• 9.88 billion years (3.92 Gya):
  Nectaris Basin forms from large impact event: ejecta from Nectaris forms upper part of densely cratered Lunar Highlands – Nectarian
  Era begins on the Moon.
• 9.9 billion years (3.9 Gya):
  Caloris Basin forms on Mercury leading to creation of "Weird Terraine" – seismic activity triggers volcanic activity globally on Mercury. Rembrandt (crater) formed on Mercury. Caloris Period begins on Mercury. Argyre Planitia forms from asteroid impact on Mars: surrounded by rugged massifs which form concentric and radial patterns around basin – several mountain ranges including Charitum and Nereidum Montes
  are uplifted in its wake
• 9.95 billion years (3.85 Gya): Beginning of
  Late
  Imbrium Period on Moon. Earliest appearance of Procellarum KREEP Mg suite materials
• 9.96 billion years (3.84 Gya): Formation of
  Orientale Basin from asteroid impact on Lunar surface – collision causes ripples in crust, resulting in three concentric circular features known as Montes Rook and Montes Cordillera
• 10 billion years (3.8 Gya): In the wake of Late Heavy Bombardment impacts on the Moon, large molten mare depressions dominate lunar surface – major period of Lunar vulcanism begins (to 3 Gyr). Archean eon begins on the Earth.
• 10.2 billion years (3.6 Gya): Alba Mons forms on Mars, largest volcano in terms of area
• 10.4 billion years (3.5 Gya): Earliest fossil traces of life on Earth (stromatolites)
• 10.6 billion years (3.2 Gya): Amazonian Period begins on Mars: Martian climate thins to its present density: groundwater stored in upper crust (megaregolith) begins to freeze, forming thick cryosphere overlying deeper zone of liquid water – dry ices composed of frozen carbon dioxide form Eratosthenian period begins on the Moon: main geologic force on the Moon becomes impact cratering
• 10.8 billion years (3 Gya):
  Beethoven Basin
  forms on Mercury – unlike many basins of similar size on the Moon, Beethoven is not multi ringed and ejecta buries crater rim and is barely visible
• 11.2 billion years (2.5 Gya): Proterozoic begins
• 11.6 billion years (2.2 Gya): Last great tectonic period in Martian geologic history: Valles Marineris, largest canyon complex in the Solar System, forms – although some suggestions of thermokarst activity or even water erosion, it is suggested Valles Marineris is rift fault

Recent history

• 11.8 billion years (2 Gya): Star formation in Andromeda Galaxy slows. Formation of Hoag's Object from a galaxy collision. Olympus Mons, the largest volcano in the Solar System, is formed
• 12.1 billion years (1.7 Gya):
  Sagittarius Dwarf Elliptical Galaxy
  captured into an orbit around Milky Way Galaxy
• 12.7 billion years (1.1 Gya): Copernican Period begins on Moon: defined by impact craters that possess bright optically immature ray systems
• 12.8 billion years (1 Gya): The Kuiperian Era (1 Gyr – present) begins on Mercury: modern Mercury, a desolate cold planet that is influenced by space erosion and solar wind extremes. Interactions between Andromeda and its companion galaxies Messier 32 and Messier 110. Galaxy collision with Messier 82 forms its patterned spiral disc: galaxy interactions between NGC 3077 and Messier 81; Saturn's moon Titan begins evolving the recognisable surface features that include rivers, lakes, and deltas
• 13 billion years (800
  Mya): Copernicus (lunar crater)
  forms from the impact on the Lunar surface in the area of Oceanus Procellarum – has terrace inner wall and 30  km wide, sloping rampart that descends nearly a kilometre to the surrounding mare
• 13.175 billion years (625 Mya): formation of Hyades star cluster: consists of a roughly spherical group of hundreds of stars sharing the same age, place of origin, chemical content and motion through space
• 13.15-21 billion years (590–650 Mya): Capella star system forms
• 13.2 billion years (600 Mya): Collision of spiral galaxies leads to the creation of
  Antenna Galaxies. Whirlpool Galaxy collides with NGC 5195 forming a present connected galaxy system. HD 189733 b forms around parent star HD 189733
  : the first planet to reveal the climate, organic constituencies, even colour (blue) of its atmosphere
• 13.345 billion years (455 Mya): Vega, the fifth-brightest star in Earth's galactic neighbourhood, forms.
• 13.6–13.5 billion years (300-200 Mya): Sirius, the brightest star in the Earth's sky, forms.
• 13.7 billion years (100 Mya): Formation of Pleiades Star Cluster
• 13.73 billion years (70 Mya): North Star, Polaris, one of the significant navigable stars, forms
• 13.780 billion years (20 Mya): Possible formation of Orion Nebula
• 13.788 billion years (12 Mya): Antares forms.
• 13.792 billion years (7.6 Mya): Betelgeuse forms.
• 13.8 billion years (Without uncertainties): Present day.^[12]

See also

• Chronology of the universe
• Timeline of natural history (formation of the Earth to evolution of modern humans)
• Detailed logarithmic timeline
• Timeline of the far future
• Timelines of world history

References