Attempts have been made to determine a relationship between these orbital distances for example, the Titius—Bode law ,  but no such theory has been accepted. The images at the beginning of this section show the orbits of the various constituents of the Solar System on different scales. Some Solar System models attempt to convey the relative scales involved in the Solar System on human terms. Some are small in scale and may be mechanical—called orreries —whereas others extend across cities or regional areas.
Distances of selected bodies of the Solar System from the Sun. The left and right edges of each bar correspond to the perihelion and aphelion of the body, respectively, hence long bars denote high orbital eccentricity. The radius of the Sun is 0. As the region that would become the Solar System, known as the pre-solar nebula ,  collapsed, conservation of angular momentum caused it to rotate faster. The centre, where most of the mass collected, became increasingly hotter than the surrounding disc.
Hundreds of protoplanets may have existed in the early Solar System, but they either merged or were destroyed, leaving the planets, dwarf planets, and leftover minor bodies. Due to their higher boiling points, only metals and silicates could exist in solid form in the warm inner Solar System close to the Sun, and these would eventually form the rocky planets of Mercury, Venus, Earth, and Mars.
Because metallic elements only comprised a very small fraction of the solar nebula, the terrestrial planets could not grow very large. The giant planets Jupiter, Saturn, Uranus, and Neptune formed further out, beyond the frost line, the point between the orbits of Mars and Jupiter where material is cool enough for volatile icy compounds to remain solid. The ices that formed these planets were more plentiful than the metals and silicates that formed the terrestrial inner planets, allowing them to grow massive enough to capture large atmospheres of hydrogen and helium, the lightest and most abundant elements.
Leftover debris that never became planets congregated in regions such as the asteroid belt , Kuiper belt , and Oort cloud. The Nice model is an explanation for the creation of these regions and how the outer planets could have formed in different positions and migrated to their current orbits through various gravitational interactions.
Within 50 million years, the pressure and density of hydrogen in the centre of the protostar became great enough for it to begin thermonuclear fusion. At this point, the Sun became a main-sequence star. This will mark the end of the Sun's main-sequence life.
The Solar System
At this time, the core of the Sun will contract with hydrogen fusion occurring along a shell surrounding the inert helium, and the energy output will be much greater than at present. The outer layers of the Sun will expand to roughly times its current diameter, and the Sun will become a red giant. Because of its vastly increased surface area, the surface of the Sun will be considerably cooler 2, K at its coolest than it is on the main sequence.
Eventually, the core will be hot enough for helium fusion; the Sun will burn helium for a fraction of the time it burned hydrogen in the core. The Sun is not massive enough to commence the fusion of heavier elements, and nuclear reactions in the core will dwindle.
Its outer layers will move away into space, leaving a white dwarf , an extraordinarily dense object, half the original mass of the Sun but only the size of Earth. The Sun is the Solar System's star and by far its most massive component. Its large mass , Earth masses ,  which comprises The Sun is a G2-type main-sequence star. Hotter main-sequence stars are more luminous. The Sun's temperature is intermediate between that of the hottest stars and that of the coolest stars.
The Sun is a population I star ; it has a higher abundance of elements heavier than hydrogen and helium " metals " in astronomical parlance than the older population II stars. The oldest stars contain few metals, whereas stars born later have more. This high metallicity is thought to have been crucial to the Sun's development of a planetary system because the planets form from the accretion of "metals". The vast majority of the Solar System consists of a near- vacuum known as the interplanetary medium. Along with light , the Sun radiates a continuous stream of charged particles a plasma known as the solar wind.
This stream of particles spreads outwards at roughly 1. Earth's magnetic field stops its atmosphere from being stripped away by the solar wind. The interaction of this magnetic field and material with Earth's magnetic field funnels charged particles into Earth's upper atmosphere, where its interactions create aurorae seen near the magnetic poles. The heliosphere and planetary magnetic fields for those planets that have them partially shield the Solar System from high-energy interstellar particles called cosmic rays. The density of cosmic rays in the interstellar medium and the strength of the Sun's magnetic field change on very long timescales, so the level of cosmic-ray penetration in the Solar System varies, though by how much is unknown.
The interplanetary medium is home to at least two disc-like regions of cosmic dust. The first, the zodiacal dust cloud , lies in the inner Solar System and causes the zodiacal light. It was likely formed by collisions within the asteroid belt brought on by gravitational interactions with the planets. The inner Solar System is the region comprising the terrestrial planets and the asteroid belt. This region is also within the frost line , which is a little less than 5 AU about million km from the Sun.
The four terrestrial or inner planets have dense, rocky compositions, few or no moons , and no ring systems. They are composed largely of refractory minerals, such as the silicates—which form their crusts and mantles —and metals, such as iron and nickel, which form their cores.
Three of the four inner planets Venus, Earth and Mars have atmospheres substantial enough to generate weather; all have impact craters and tectonic surface features, such as rift valleys and volcanoes. The term inner planet should not be confused with inferior planet , which designates those planets that are closer to the Sun than Earth is i. Mercury and Venus. Asteroids except for the largest, Ceres, are classified as small Solar System bodies [e] and are composed mainly of refractory rocky and metallic minerals, with some ice. Asteroids smaller than one meter are usually called meteoroids and micrometeoroids grain-sized , depending on different, somewhat arbitrary definitions.
The asteroid belt occupies the orbit between Mars and Jupiter, between 2. It is thought to be remnants from the Solar System's formation that failed to coalesce because of the gravitational interference of Jupiter. The outer region of the Solar System is home to the giant planets and their large moons.
The centaurs and many short-period comets also orbit in this region. Due to their greater distance from the Sun, the solid objects in the outer Solar System contain a higher proportion of volatiles, such as water, ammonia, and methane than those of the inner Solar System because the lower temperatures allow these compounds to remain solid.
For these reasons, some astronomers suggest they belong in their own category, ice giants. The term superior planet designates planets outside Earth's orbit and thus includes both the outer planets and Mars. The centaurs are icy comet-like bodies whose orbits have semi-major axes greater than Jupiter's 5. Comets are small Solar System bodies, [e] typically only a few kilometres across, composed largely of volatile ices.
They have highly eccentric orbits, generally a perihelion within the orbits of the inner planets and an aphelion far beyond Pluto. When a comet enters the inner Solar System, its proximity to the Sun causes its icy surface to sublimate and ionise , creating a coma : a long tail of gas and dust often visible to the naked eye. Short-period comets have orbits lasting less than two hundred years. Long-period comets have orbits lasting thousands of years.
Short-period comets are thought to originate in the Kuiper belt, whereas long-period comets, such as Hale—Bopp , are thought to originate in the Oort cloud. Many comet groups, such as the Kreutz Sungrazers , formed from the breakup of a single parent. Beyond the orbit of Neptune lies the area of the " trans-Neptunian region ", with the doughnut-shaped Kuiper belt, home of Pluto and several other dwarf planets, and an overlapping disc of scattered objects, which is tilted toward the plane of the Solar System and reaches much further out than the Kuiper belt.
The entire region is still largely unexplored. It appears to consist overwhelmingly of many thousands of small worlds—the largest having a diameter only a fifth that of Earth and a mass far smaller than that of the Moon—composed mainly of rock and ice. This region is sometimes described as the "third zone of the Solar System", enclosing the inner and the outer Solar System.
The Kuiper belt is a great ring of debris similar to the asteroid belt, but consisting mainly of objects composed primarily of ice. Though it is estimated to contain anything from dozens to thousands of dwarf planets, it is composed mainly of small Solar System bodies. Many of the larger Kuiper belt objects, such as Quaoar , Varuna , and Orcus , may prove to be dwarf planets with further data. The Kuiper belt can be roughly divided into the " classical " belt and the resonances.
Why Mercury Isn't The Solar System's Hottest Planet
The first resonance begins within the orbit of Neptune itself. The classical belt consists of objects having no resonance with Neptune, and extends from roughly The scattered disc, which overlaps the Kuiper belt but extends much further outwards, is thought to be the source of short-period comets. Scattered-disc objects are thought to have been ejected into erratic orbits by the gravitational influence of Neptune's early outward migration. SDOs' orbits are also highly inclined to the ecliptic plane and are often almost perpendicular to it.
Some astronomers consider the scattered disc to be merely another region of the Kuiper belt and describe scattered disc objects as "scattered Kuiper belt objects". The point at which the Solar System ends and interstellar space begins is not precisely defined because its outer boundaries are shaped by two separate forces: the solar wind and the Sun's gravity. The limit of the solar wind's influence is roughly four times Pluto's distance from the Sun; this heliopause , the outer boundary of the heliosphere , is considered the beginning of the interstellar medium.
The outer boundary of the heliosphere, the heliopause , is the point at which the solar wind finally terminates and is the beginning of interstellar space. The shape and form of the outer edge of the heliosphere is likely affected by the fluid dynamics of interactions with the interstellar medium as well as solar magnetic fields prevailing to the south, e. Due to a lack of data, conditions in local interstellar space are not known for certain. It is expected that NASA 's Voyager spacecraft , as they pass the heliopause, will transmit valuable data on radiation levels and solar wind to Earth.
Mike Brown , who discovered the object in , asserts that it cannot be part of the scattered disc or the Kuiper belt because its perihelion is too distant to have been affected by Neptune's migration. The second unequivocally detached object, with a perihelion farther than Sedna's at roughly 81 AU, is VP , discovered in Its aphelion is only half that of Sedna's, at — AU. It is thought to be composed of comets that were ejected from the inner Solar System by gravitational interactions with the outer planets.
Oort cloud objects move very slowly, and can be perturbed by infrequent events, such as collisions, the gravitational effects of a passing star, or the galactic tide , the tidal force exerted by the Milky Way. Much of the Solar System is still unknown. The Sun's gravitational field is estimated to dominate the gravitational forces of surrounding stars out to about two light years , AU.
Lower estimates for the radius of the Oort cloud, by contrast, do not place it farther than 50, AU. There are also ongoing studies of the region between Mercury and the Sun. Currently, the furthest known objects, such as Comet West , have aphelia around 70, AU from the Sun, but as the Oort cloud becomes better known, this may change. This revolution is known as the Solar System's galactic year.
Tonight's Sky — Change location
The Solar System's location in the Milky Way is a factor in the evolutionary history of life on Earth. Its orbit is close to circular, and orbits near the Sun are at roughly the same speed as that of the spiral arms. Because spiral arms are home to a far larger concentration of supernovae , gravitational instabilities, and radiation that could disrupt the Solar System, this has given Earth long periods of stability for life to evolve.
Near the centre, gravitational tugs from nearby stars could perturb bodies in the Oort cloud and send many comets into the inner Solar System, producing collisions with potentially catastrophic implications for life on Earth. The intense radiation of the galactic centre could also interfere with the development of complex life. It is thought to be near the neighbouring G-Cloud but it is not known if the Solar System is embedded in the Local Interstellar Cloud, or if it is in the region where the Local Interstellar Cloud and G-Cloud are interacting.
The bubble is suffused with high-temperature plasma, that suggests it is the product of several recent supernovae. There are relatively few stars within ten light-years of the Sun. The closest is the triple star system Alpha Centauri , which is about 4. Alpha Centauri A and B are a closely tied pair of Sun-like stars, whereas the small red dwarf , Proxima Centauri , orbits the pair at a distance of 0. In , a potentially habitable exoplanet was confirmed to be orbiting Proxima Centauri, called Proxima Centauri b , the closest confirmed exoplanet to the Sun.
The largest nearby star is Sirius , a bright main-sequence star roughly 8. The nearest brown dwarfs are the binary Luhman 16 system at 6. Other systems within ten light-years are the binary red-dwarf system Luyten 8. Compared to many other planetary systems , the Solar System stands out in lacking planets interior to the orbit of Mercury. Also, these super-Earths have closer orbits than Mercury.
The orbits of Solar System planets are nearly circular. Compared to other systems, they have smaller orbital eccentricity. This section is a sampling of Solar System bodies, selected for size and quality of imagery, and sorted by volume. Some omitted objects are larger than the ones included here, notably Eris , because these have not been imaged in high quality. From Wikipedia, the free encyclopedia. This article is about the Sun and its planetary system. For other similar systems, see Planetary system.
Planetary system of the Sun. The Sun and planets distances not to scale. Gravitationally-rounded equilibrium objects. Comets Asteroids. Main article: Discovery and exploration of the Solar System. All planets of the Solar System lie very close to the ecliptic. The closer they are to the Sun, the faster they travel inner planets on the left, all planets except Neptune on the right. The Solar System. Distances are to scale, objects are not.
Main article: Formation and evolution of the Solar System. The geology of MU 69 "Ultima Thule" , the first undisturbed planetesimal visited by a spacecraft, with comet 67P to scale. Notable surface features are highlighted at right. The eight subunits of the larger lobe, labeled ma to mh , are thought to have been its building blocks. The two lobes came together later, forming a contact binary. Objects such as MU 69 are believed in turn to have formed protoplanets.
Main article: Sun. Main articles: Interplanetary medium and Solar wind. Main article: Terrestrial planet. Main article: Mercury planet.
Main article: Venus. Main article: Earth. Main article: Mars. Main article: Asteroid belt. Main article: Ceres dwarf planet. Main article: Giant planet. Main article: Jupiter. Main article: Saturn. Main article: Uranus. Main article: Neptune. Main article: Centaur minor planet. Main article: Comet. Main article: Kuiper belt. Main articles: Pluto and Charon moon. Main articles: Makemake and Haumea. Main article: Scattered disc. Main article: Eris dwarf planet. Main article: Heliosphere. Main articles: Detached object and Sednoid. Main article: Oort cloud.
Diagram of the Milky Way with the position of the Solar System marked by a yellow arrow. This box: view talk edit. Astronomical symbols Earth phase Ephemeris is a compilation of positions of naturally occurring astronomical objects as well as artificial satellites in the sky at a given time or times. The International Astronomical Union , the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects, but uses mixed "Solar System" and "solar system" in their naming guidelines document.
The name is commonly rendered in lower case " solar system " , as, for example, in the Oxford English Dictionary and Merriam-Webster's 11th Collegiate Dictionary. See Former planets. Although bigger than Mercury, both moons have less than half its mass. A planet is any body orbiting the Sun whose mass is sufficient for gravity to have pulled it into a near- spherical shape and that has cleared its immediate neighbourhood of all smaller objects. Because it has not cleared its neighbourhood of other Kuiper belt objects, Pluto does not fit this definition. Both pairs of coordinates are for J epoch.
The result of the calculation is Mike Brown's Planets. Retrieved 20 April Robert Johnston 12 April Johnston's Archive. Retrieved 21 May Advances in Space Research. Bibcode : AdSpR.. Archived from the original on 7 January Retrieved 2 March Geological Survey. Retrieved 13 July International Astronomical Union. Archived from the original on 3 June Retrieved 13 October International Astronomical Union , Paris. Archived from the original on 13 June Retrieved 11 June Archived from the original on 13 November Popular Astronomy.
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Retrieved 19 January Retrieved 18 March All the same, this was mainly confined to the earth and moon.
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More recently, Dr Faulkner has developed his idea about cratering during creation week to explain the cratering elsewhere in the solar system, arguing that most happened on Day 4. This would not violate the pre-Fall goodness of creation because no nephesh chayyah would be hurt.
Venus and Mercury
Doug B. AU August 14th, As you know, they won't show sensible programs on these subjects but continue to push out the evolution nonsense. On ABC radio there was news about something that had been found in Australia this week that was M years old with no explanation of how they knew this. Kirk B. CZ August 14th, Brian Cox is a great storyteller with a rich imagination. He should perhaps transfer to a position in creative writing. I have thought of the same possible scenario during the Flood, that could have impacted the other planets making them uninhabitable.
Did God perhaps have ideas for man and these other planets before this Judgment on earth occurred? This is probably unknowable, but it makes me smile to think of all the possibilities that the Lord is capable of doing. Raymond S. US August 14th, Every rocky planet shows signs of four phases: formation, bombardment, recovery, and modern conditions.
For the Moon, it is formation lunar highlands , bombardment massive craters , recovery maria lava flows , and the present. And, they put the words in his mouth that they thought was wanted to be heard. A soothing bedtime story, not real science. And, when we as a Christian community believe him, we have believed fairy tales.
But, we also need to consider that many fossil layers on earth are tied up in sediments that appear to be associated with cratering deposits, like the Morrison Formation, the largest source of dinosaur fossils in the US. It centers on an apparent crater in southern Wyoming, Bridger Basin, and its boundaries of deposition are limited by circular formations that resemble impact produced events. Gerry T. CA August 14th, I would have thought Dr Cox was intelligent enough to know the sun does not actually rise, it only appears to do so for observers on a rotating planetary body.
Jonathan Sarfati August 14th, Of course he knows that. Also, sometimes Scripture uses a different reference frame from earth, e. He claims for the first several million years of the sun's existence there were no planets to witness its rise. According to his view the planets arose slowly over the next several million years due to the constant colliding and accumulation of dust into rocks and the resulting rocks into the planets of the inner solar system.
As Dr Cox is obviously an intelligent man one would assume he is aware that the constant colliding of rocky particles is going to result in erosion not accumulation. Instead of going from dust to rocks this process would result in rocks going to dust. Pratha S. US August 15th, Once again, we have evolutionists saying that the planets—indeed the whole universe—is old.
The Bible is clear that this is simply not the case—and God would certainly know better than man would. Errol B. AU August 15th, If the moon was completely void of craters, how much less visibility would there be during a full moon? Jonathan Sarfati August 15th, Actually, the lunar maria are solidified flows of basalt lava, and basalt is a dark, sometimes black, rock.
Andrei A. RO August 15th, One to change the orbit to an elliptical one with the periapsis closer to the sun and then another slow dow to bring the apoapsis to where it is today? Just like the comets that come close to the sun but they are never slowed down and captured into a low Sun orbit as their speeds shoot them back up. When we send a spacecraft to another planet we do need to slow it down to enter a stable orbit. Philip G. AU August 18th, The Bible only records the consequences on Earth. The cratering of the inner planets and moons, is enigmatic if one considers meteorites.
All the craters are roundish, indicating that all the meteors fell to the surfaces, with their trajectory towards the center of the planet or moon. There are no glancing craters. They are all roundish. My conclusion is, that craters are not all formed by meteorites. The actual shape of the craters is roughly hexagonal, with a small raised center, which is atypical of impacts.
The shape is however, typical of electrical arcs. My thought is that the cataclysm of the flood period, was more widespread than planet Earth. It seems that the whole solar system was affected. Even Pluto has evidence of cratering. Our solar system is heliocentric, so whatever happens to the sun, affects the whole system. It is all the planets that we can measure. Similarly, when God warned Noah of a flood to come, was He about to change the other planets as well? I believe so.
Earth as we know it today, is vastly different to the pre-flood world. Everything changed dramatically. Mercury and Venus too, I surmise, are very different to their pre-flood forms. Max O. AU August 22nd, I have looked for it, but cannot find it. Jonathan Sarfati August 23rd, And since dynamo theories are especially problematic for Mercury because it is so small that it should not still have a liquid core after the assumed billions of years, and exponential decay from its last addition of energy is a normal type of decay in nature , it was reasonable to work out a decay constant from the measurements.
Don't attack individuals, denominations, or other organizations. Stay on-topic.