In the Dust of This Planet: Horror of Philosophy

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Within 50million years, the temperature and pressure at the core of the Sun became so great that its hydrogen began to fuse, creating an internal source of energy that countered gravitational contraction until hydrostatic equilibrium was achieved. [29] This marked the Sun's entry into the prime phase of its life, known as the main sequence. Main-sequence stars derive energy from the fusion of hydrogen into helium in their cores. The Sun remains a main-sequence star today. [30] The nebular hypothesis says that the Solar System formed from the gravitational collapse of a fragment of a giant molecular cloud, [9] most likely at the edge of a Wolf-Rayet bubble. [10] The cloud was about 20 parsecs (65 light years) across, [9] while the fragments were roughly 1parsec (three and a quarter light-years) across. [11] The further collapse of the fragments led to the formation of dense cores 0.01–0.1parsec (2,000–20,000 AU) in size. [a] [9] [12] One of these collapsing fragments (known as the presolar nebula) formed what became the Solar System. [13] The composition of this region with a mass just over that of the Sun ( M ☉) was about the same as that of the Sun today, with hydrogen, along with helium and trace amounts of lithium produced by Big Bang nucleosynthesis, forming about 98% of its mass. The remaining 2% of the mass consisted of heavier elements that were created by nucleosynthesis in earlier generations of stars. [14] Late in the life of these stars, they ejected heavier elements into the interstellar medium. [15] Some scientists have given the name Coatlicue to a hypothetical star that went supernova and created the presolar nebula.

One key insight made possible with the VMC images is the measurement of the altitude of dust clouds. The length of the shadows they cast are measured and combined with knowledge of the Sun’s position to measure the height of the clouds above the martian surface. Results revealed that dust can reach approximately 6–11 km above the ground and the cells have typical horizontal sizes of 20–40 km.Gregory says, 'Near to the Sun, the temperature was very high, so minerals and metals formed. And on the edge of the disc, far away from the heat of the Sun, less volatile solids like ice and ammonia formed. Uranus holds the record for the coldest temperature ever measured in the solar system — minus 371.56 degrees F (minus 224.2 degrees C). The average temperature of Uranus is minus 320 degrees Fahrenheit (-195 degrees Celsius). For millennia, astronomers have followed points of light that seemed to move among the stars. The ancient Greeks named them planets, meaning "wanderers." Mercury, Venus, Mars, Jupiter and Saturn were known in antiquity, and the invention of the telescope added the Asteroid Belt, Uranus, Neptune, Pluto and many of these worlds' moons. The dawn of the space age saw dozens of probes launched to explore our system, an adventure that continues today.

Formation of the Solar System after gas and dust accretion to a protoplanetary disk. The vast majority of this material was created from the primal supernova The images reveal a particular phenomenon on Mars. They show that the martian dust storms are made up of regularly spaced smaller cloud cells, arranged like grains or pebbles. The texture is also seen in clouds in Earth’s atmosphere. Brown, Michael E., and Konstantin Batygin. " Observational constraints on the orbit and location of planet nine in the outer solar system." The Astrophysical Journal Letters 824.2 (2016): L23. Radiolab - In The Dust Of This Planet", original broadcast Monday September 8, 2014. The story was also covered by NPR's On The Media. The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. [1] Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed.According to the Nice model, after the formation of the Solar System, the orbits of all the giant planets continued to change slowly, influenced by their interaction with the large number of remaining planetesimals. After 500–600million years (about 4billion years ago) Jupiter and Saturn fell into a 2:1 resonance: Saturn orbited the Sun once for every two Jupiter orbits. [44] This resonance created a gravitational push against the outer planets, possibly causing Neptune to surge past Uranus and plough into the ancient Kuiper belt. [66] As the early Solar System continued to evolve, it eventually drifted away from its siblings in the stellar nursery, and continued orbiting the Milky Way's center on its own. The Sun likely drifted from its original orbital distance from the center of the galaxy. The chemical history of the Sun suggests it may have formed as much as 3kpc closer to the galaxy core. [31] Solar system birth environment [ edit ]