Solar system
A genericogólny solar systemukład słoneczny (or planetary system) consists of at least one star and various orbitingto orbit: krążyć wokół objects (such as asteroids, comets, moons, and planets). The term originated to describe the planetary system around Sol, the Latin name for our sun. The planet Earth is located within our solar systemukład słoneczny, which is usually called simply the Solar system; others are called planetary systems to avoid confusionzamieszanie. This article uses this terminology.
Solar system objects
The wide variety of objects that exist in the solar systemukład słoneczny fall into several
categories. In recent years many of these categories have been found to be less
clear-cutwyraźny than once thought. This encyclopedia employs the following divisionspodziały:
- The Sun is a spectralwidmowy, spektralny class G2 star that contains 99.86% of the system's
mass.
- The planets of the solar systemukład słoneczny are those nine bodies traditionally labelledto label: oznaczać
as such: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and
Pluto.
- Sizeable objects that orbit these planets are moons. For
a complete listing, see that article.
- Dust and other small particlesdrobinki, cząstkicząstki that orbit these planets
form planetary rings.
- Space debrisgruz of artificialsztuczne originpochodzenie that can be found in
orbit around Earth.
- Planetesimals, from which the planets were originally
formed, are sub-planetary bodies that accretedto accrete: narastać, gromadzić się during the first years
of the solar systemukład słoneczny and that no longer exist. The name is also sometimes
used to refer to asteroids and comets in general, or to asteroids belowponiżej
10km in diameterśrednica.
- Asteroids are objects smaller than planets that lie roughlyw przybliżeniu
within the orbit of Jupiter and are composed in significant part of nonvolatile
minerals. They are subdividedto subdivide: dzielić na mniejsze częścito subdivide: dzielić się dalej into asteroid groups and asteroid families based
on their specific orbital characteristicswłaściwości.
- Asteroid moons are asteroids that orbit larger asteroids.
They are not as clearly distinguishedto distinguish: odróżniać as planetary moons, sometimes being
almost as large as their partners.
- Trojan asteroids are located in either of Jupiter's L4
or L5 points, though the term is also sometimes used for asteroids
in any other planetary Lagrange point as well.
- Meteoroids are asteroids that range in size from roughlyw przybliżeniu
bouldergłaz sized to particlesdrobinki, cząstkicząstki as small as dust.
- Comets are composed largely of volatileniestabilne, lotne ices and have highly
eccentricwydłużony orbits, generally having a periapsis within the orbit of the innerwewnętrzny
planets and an apoapsis beyond Pluto. Short-period comets exist with apoapses
closer than this, however, and old comets that have had most of their volatiles
driven out by solar warming are often categorizedto categorize: klasyfikować as asteroids. Some comets
with hyperbolic orbits may also originatepowstaćzapoczątkować outside the solar systemukład słoneczny.
- Centaurs are icylodowe comet-like bodies that have less-eccentricwydłużony
orbits so that they remainpozostawać in the region between Jupiter and Neptune.
- Trans-Neptunian objects, which are icylodowe bodies whose mean orbital
radiuspromień lies beyond Neptune's. These are further subdividedto subdivide: dzielić na mniejsze częścito subdivide: dzielić się dalej:
- Kuiper beltpas, strefa objects have orbits lying between 30 and 50
AU. This is thought to be the originpochodzenie for short-period comets. Pluto is
sometimes classified as a Kuiper beltpas, strefa object in addition to being a planet,
and a class of Kuiper beltpas, strefa objects with Pluto-like orbits are called Plutinos.
The remainingpozostający Kuiper beltpas, strefa objects are classified as Cubewanos in the main
beltpas, strefa and scatteredrozrzucony, rozproszony disk objects in the outerzewnętrzny fringeskrawędzie.
- Oort cloud objects, currently hypotheticalhipotetyczny, have orbits
lying between 50,000 and 100,000 AU. This region is thought to be the
originpochodzenie of long-period comets.
- The newly discovered object Sedna, with a highly elliptical
orbit extendingto extend: rozciągać się from about 76 to 850 AU, does not obviouslyoczywiście fitpasować in either
category, although its discoverersodkrywcy arguespierać sie that it should be consideredto consider: uważać za
a part of the Oort cloud.
- Small quantitiesilości of dust are present throughoutprzez cały the solar
system and are responsible for the phenomenon of zodiacal light. Some of the
dust is likely interstellarmiędzygwiezdny dust from outside the solar systemukład słoneczny.
Origin and evolution of planetary systems
Planetary systems are generally believed to form as part of the same process which results in star formation; although, some
arguespierać sie that systems are formed by some kind of accidental "
stellargwiezdny near-collison". The more common theory argues that the objects of a planetary system
developedto develop: rozwijać się from a solar
nebulamgławica.
Orbit of the
solar systemukład słonecznyThe
solar systemukład słoneczny is part of the Milky Way
galaxygalaktyka, a spiral
galaxygalaktyka with a
diameterśrednica of about 100,000 light years containing approximately 200 billion stars, of which our Sun is
fairlydośc, dosyć typical.
Estimates place the
solar systemukład słoneczny at between 25,000 and 28,000 light years from the galactic center. Its speed is about 220 kilometers per second, and it completes one
revolutionobieg every 226 million years.
The
solar systemukład słoneczny appears to have a very unusual orbit. It is both extremely close to being circular, and at nearly the exact distance at which the orbital speed matches the speed of the
compressionściskanie waves that form the spiral arms. The
solar systemukład słoneczny appears to have remained between spiral arms for most of the existence of life on Earth. The
radiationpromieniowanie from supernovae in spiral arms could theoretically sterilize planetary
surfacespowierzchnie, preventing the formation of large animal life on land. By
remainingpozostający out of the spiral arms, Earth may be unusually free to form large animal life on its
surfacepowierzchnia.
Discovery and exploration of the
solar systemukład słonecznyBecause of the geocentric perspective from which humans viewed the
solar systemukład słoneczny, its nature and structure were long
misperceivedto misperceive: błędnie postrzegać. The
apparentpozorne motionsruchy of
solar systemukład słoneczny objects as viewed from a moving Earth were believed to be their
actualrzeczywiste motionsruchy about a
stationarynieruchomy Earth. In addition, many
solar systemukład słoneczny objects and phenomena are not directly
sensiblepostrzegalny by humans without technical
aidspomoce. Thus both
conceptualpojęciowe and technological
advancespostępy were required in order for the
solar systemukład słoneczny to be correctly understood.
The first and most
fundamentalpodstawowe of these
advancespostępy was the Copernican Revolution, which adopted a heliocentric model for the
motionsruchy of the planets. Indeed, the term "
solar systemukład słoneczny" itself derives from this perspective. But the most important consequences of this new
perceptionpostrzeganie came not from the central position of the Sun, but from the orbital position of the Earth, which suggested that the Earth was itself a planet, and the planets other Earths. This was the first
indicationoznaka of the true nature of the planets. Also, the lack of
perceptibledostrzegalny stellargwiezdny parallax
despitepomimo the Earth's orbital motion indicated the extreme
remotenessoddalenie of the
fixednieruchomy stars, which
promptedto prompt: wywoływać the speculation that they could be objects similar to the Sun, perhaps with planets of their own.
The
solar systemukład słoneczny and other planetary systems
Until recently, the
solar systemukład słoneczny was the only known example of a planetary system, although it was widely believed that other
comparableporównywalne systems did exist. A number of such systems have now been
detectedto detect: wykrywać, although the information
availabledostępny about them is very limited. The technique employed involves the detection through the Doppler effect of periodic
variationsodmiany in the motion of parent stars which is
attributedto attribute: przypisywać to the presence of planets. This allows the mass and orbital
characteristicswłaściwości of the
unseenwcześniej nie widziany planets to be determined. Unfortunately the
sensitivitywrażliwość of these techniques currently does not
permitto permit: pozwalać na the detection of planets of mass and orbit
comparableporównywalne to the Earth.
Url źródłowy: http://en.wikipedia.org/wiki/Solar_system
Słowniczek
distinguished
to distinguish
categorized
to categorize
subdivided
to subdivide
dzielić na mniejsze części
misperceived
to misperceive