Portal:Solar System
The Solar System Portal
The fusion of hydrogen into helium at its core, releasing this energy from its outer photosphere.
The largest objects that orbit the Sun are the eight
. Over 99.86% of the Solar System's mass is in the Sun and nearly 90% of the remaining mass is in Jupiter and Saturn.There is a strong consensus among astronomers that the Solar System has at least eight
centaurs, meteoroids, and interplanetary dust clouds. Some of these bodies are in the asteroid belt (between Mars's and Jupiter's orbit) and the Kuiper belt (just outside Neptune's orbit). Six planets, six dwarf planets, and other bodies have orbiting natural satellites
, which are commonly called 'moons'.
The Solar System is constantly flooded by the Sun's
long-period comets, extending 2,000–200,000 astronomical units (0.032–3.2 light-years). The closest star to the Solar System, Proxima Centauri, is 4.25 light-years away. Both stars belong to the Local Group and the Milky Way galaxy. (Full article...
)
Selected article –
Selected picture
-
Photograph credit: NASA / JPL–Caltech / University of ArizonaAlthough Mars is smaller than the Earth and 50 percent farther from the Sun, its climate has important similarities with the Earth, such as the presence of polar ice caps, seasonal changes and observable weather patterns. This image shows layered deposits in Planum Boreum, in the north polar region of Mars, which formed from a 3-kilometre-thick (2 mi) stack of dusty water-ice layers about 1,000 km (600 mi) across. The layers record information about the climate of the planet stretching back several million years. Erosion has created scarps and troughs that expose the layering. The tan-colored layers are the dusty water ice of the polar layered deposits, however a section of bluish layers is visible below them. These bluish layers contain sand-sized rock fragments that likely formed a large polar dunefield before the overlying dusty ice was deposited. This photograph, depicting an area approximately 1.3 km (0.8 mi) across, was captured by the HiRISE camera on board NASA's Mars Reconnaissance Orbiter.
-
The Milky Way is the galaxy that contains the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term Milky Way is a translation of the Latin via lactea, from the Greek γαλαξίας κύκλος (galaxías kýklos, 'milky circle'). From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies.
This picture shows a portion of the Milky Way as seen from Cerro Paranal in Chile, home to the European Southern Observatory (ESO)'s Very Large Telescope, depicting the region spanning the constellations from Sagittarius to Scorpius. The colourful nebulae surrounding Rho Ophiuchi and Antares can be seen to the right, while the dusty lane of the galaxy runs obliquely through the image, dotted with reddish objects such as the Lagoon and Trifid Nebulae. This region of the Milky Way also includes the Galactic Center, likely containing a supermassive black hole, Sagittarius A*. -
Credit: William AndersEarthrise, the first occasion in which humans saw the Earth seemingly rising above the surface of the Moon, taken during the Apollo 8 mission on December 24, 1968. This view was seen by the crew at the beginning of its fourth orbit around the Moon, although the first photograph taken was in black-and-white. Note that the Earth is in shadow here. A photo of a fully lit Earth would not be taken until the Apollo 17 mission.
-
These images are composites of the complete radar image collection obtained by the Magellan mission. The Magellan spacecraft was launched aboard Space Shuttle Atlantis in May 1989 and began mapping the surface of Venus in September 1990. The spacecraft continued to orbit Venus for four years, returning high-resolution images, altimetry, thermal emissions and gravity maps of 98 percent of the surface. Magellan spacecraft operations ended on October 12, 1994, when the radio contact was lost with the spacecraft during its controlled descent into the deeper portions of the Venusian atmosphere.
-
Jack Schmitt — all of whom took photographic images during the mission. Apollo 17 passed over Africa during daylight hours and Antarctica is also illuminated. The photograph was taken approximately five hours after the spacecraft's launch, while en route to the Moon. Apollo 17, notably, was the last manned lunar mission; no humans since have been at a range where taking a "whole-Earth" photograph such as "The Blue Marble" would be possible.Photograph credit: Gregory H. ReveraThe Moon is the only natural satellite of Earth and the fifth largest moon in the Solar System. Owing to its synchronous rotation around Earth, the Moon always shows essentially the same face: its near side, which is marked by dark volcanic maria, as well as the bright ancient crustal highlands and the prominent impact craters. However, variations in the Moon's orbital speed due to its orbital eccentricity cause a libration of several degrees of longitude; the alignment of the Moon's orbital plane causes a similar libration in latitude. The Moon was first reached in September 1959 by the Soviet Union's unmanned Luna 2, followed by the first successful soft landing by Luna 9 in 1966. The United States Apollo program achieved the only manned lunar missions to date, including Apollo 8 in 1968, the first manned orbital mission, as well as Apollo 11, the first of six manned landings between 1969 and 1972.
This picture shows the near side of the Moon close to its greatest northern ecliptic latitude, so the southern craters are especially prominent. Tranquility Base, Apollo 11's landing site, is located near the mid-right in the photograph.polar map of Jupiter, taken by the Cassini orbiter as it neared Jupiter during a flyby on its way to Saturn, is the most detailed global color map of the planet ever produced. The south pole is in the center of the map and the equator is at the edge. The map shows a variety of colorful cloud features, including parallel reddish-brown and white bands, the Great Red Spot, multi-lobed chaotic regions, white ovals, and many small vortexes. Many clouds appear in streaks and waves due to continual stretching and folding by Jupiter's winds and turbulence.Kreutz Sungrazer which was discovered in 2011. Named after its discoverer, Terry Lovejoy, the comet was nicknamed "The Great Christmas Comet" owing to it becoming visible near Christmas.rotation period and seasonal cycles are also similar to those of the Earth. Of all the planets in the Solar System other than Earth, Mars is the most likely to harbour liquid water and perhaps life. There are ongoing investigations assessing Mars's past potential for habitability, as well as the possibility of extant life. Future astrobiology missions are planned, including NASA's Mars 2020 rover and the European Space Agency (ESA)'s Rosalind Franklin rover. In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region of the planet. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped.
This picture is a true-colour image of Mars, taken from a distance of about 240,000 kilometres (150,000 mi) by the OSIRIS instrument on ESA's Rosetta spacecraft, during its February 2007 flyby of the planet. The image was generated using OSIRIS's orange (red), green and blue filters.A TRACE image of sunspots on the surface, or photosphere, of the Sun from September 2002, is taken in the far ultraviolet on a relatively quiet day for solar activity. However, the image still shows a large sunspot group visible as a bright area near the horizon. Although sunspots are relatively cool regions on the surface of the Sun, the bright glowing gas flowing around the sunspots have a temperature of over one million °C (1.8 million °F). The high temperatures are thought to be related to the rapidly changing magnetic field loops that channel solar plasma.probe has been able to survive more than a few hours on Venus's surface, which is completely obscured by clouds, because the atmospheric pressure is some 90 times that of the Earth's, and its surface temperature is around 450 °C (842 °F).The transit of Mercury across the face of the Sun that took place in November 2006. Mercury appears as a black speck in the Sun's lower center-right region; the black areas on the left and right edges are sunspots. The transit was first recorded by French astronomer Pierre Gassendi on November 7, 1631. Transits of Mercury take place in May or November, at intervals of 7, 13, or 33 years, with the next one scheduled to appear in May 2016.Kelvin MaThe Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear-fusion reactions in its core, radiating the energy mainly as visible light and infrared radiation. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometres (860,000 mi), or 109 times that of Earth. Its mass is about 330,000 times that of Earth, and accounts for about 99.86 percent of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen; the rest is mostly helium, with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. This diagram illustrates the general structure of the Sun, with all features drawn to scale.Jupiter-family comet, which was originally from the Kuiper belt, is about 4.3 km (2.7 mi) across, has a current orbital period of 6.45 years, a rotation period of approximately 12.4 hours, and a maximum velocity of 135,000 km/h (38 km/s; 84,000 mph). It was first observed on photographic plates in 1969 by Soviet astronomers Klim Churyumov and Svetlana Gerasimenko, after whom it is named.2004, and the next pair of transits will occur in 2117 and 2125.Eugene Cernan makes a short test drive of the lunar rover (officially, Lunar Roving Vehicle or LRV) during the early part of the first Apollo 17 extravehicular activity. The LRV was only used in the last three Apollo missions, but it performed without any major problems and allowed the astronauts to cover far more ground than in previous missions. All three LRVs were abandoned on the Moon.stitched image is composed of 405 individual images taken with five different filters on the panoramic camera over the course of five Martian days.Lakes of methane onfalse-color radar image taken by the Cassini orbiter provides convincing evidence for large bodies of liquid methane on Titan. Images taken during a fly-by of the moon on July 22, 2006 show more than 75 large bodies of liquid ranging in diameter from three to 70km (1.9 to 43.6 mi) in the moon's northern hemisphere. Intensity in this colorized image is proportional to how much radar brightness is returned. The lakes, darker than the surrounding terrain, are emphasized here by tinting regions of low backscatter in blue. Radar-brighter regions are shown in tan. Smallest details in this image are about 500 m (1,640 ft) across. On January 3, 2007, NASA announced that scientists have "definitive evidence of lakes filled with methane on Saturn's moon Titan."Photograph: John VermetteC/2014 Q2 (Lovejoy) is a long-period comet discovered in 2014 by Australian astronomer Terry Lovejoy using a 0.2-meter (8 in) Schmidt–Cassegrain telescope. It was discovered at apparent magnitude 15 in the southern constellation of Puppis, and is the fifth comet discovered by Lovejoy. Its blue-green glow is the result of organic molecules and water released by the comet fluorescing under the harsh UV and optical light of the sun as it passes through space.-
orbital resonance are also marked. (from Solar System)Orbit classification of Kuiper belt objects. Some clusters that is subjected to
-
interstellar medium, with the different regions and their distances on a steped horizontal distance scale (object's size not to scale). (from Solar System)The Solar System within the
-
Artist's conception of thegiant impact thought to have formed the Moon (from Formation and evolution of the Solar System)
- Artist's conception of a
- The Sun in true white color (from
-
G-type main-sequence star. Around 11 billion years after being formed by the Solar System's protoplanetary disk, the Sun will expand to become a red giant; Mercury, Venus and possibly the Earth will be swallowed. (from Solar System)Overview of the evolution of the Sun, a
-
Theplanets, moons and dwarf planets. The asteroid belt and Kuiper beltare not added because the individual asteroids are too small to be shown on the diagram.
- Diagram of the Sun's magnetosphere and helioshealth (from
-
Simulation showing outer planets and Kuiper belt:
a) Before Jupiter/Saturn 2:1 resonance
b) Scattering of Kuiper belt objects into the Solar System after the orbital shift of Neptune
c) After ejection of Kuiper belt bodies by JupiterOrbit of JupiterOrbit of SaturnOrbit of UranusOrbit of Neptune(from Formation and evolution of the Solar System) - To-scale diagram of distance between planets, with the white bar showing orbital variations. The size of the planets is not to scale. (from
-
space weather in general. (from Solar System)Coronal mass ejections play a dominant role in the Solar System's environment and
- Relative size of the Sun as it is now (inset) compared to its estimated future size as a red giant (from
- Diagram of the Milky Way, with galactic features and the relative position of the Solar System labelled. (from
-
Meteor Crater in Arizona. Created 50,000 years ago by an impactor about 50 metres (160 ft) across, it shows that the accretion of the Solar System is not over. (from Formation and evolution of the Solar System)
-
Pierre-Simon Laplace, one of the originators of the nebular hypothesis (from Formation and evolution of the Solar System)
- Linear map of the inner Solar System, showing many asteroid populations (from
- The orbital eccentricities and inclinations of the scattered disc population compared to the classical and resonant Kuiper belt objects (from
-
Animations of the Solar System'souter planets orbiting. This animation is 100 times faster than the inner planet animation. (from Solar System)
-
Sedna and its orbit within the Solar System (from Solar System)The detached object
- Location of the Solar System within the Milky Way (from
-
Animations of the Solar System'sinner planets orbiting. Each frame represents 2 days of motion. (from Solar System)
-
Local Interstellar Cloud, the G-Cloud and surrounding stars. As of 2022, the precise location of the Solar System in the clouds is an open question in astronomy. (from Solar System)Diagram of the
-
habitable zones of the Solar System and Gliese 581 (planet d was later found to not exist). The habitable zone is highly dependent on parent star's luminosity. (from Solar System)Comparison between the
-
TheRing nebula, a planetary nebula similar to what the Sun will become (from Formation and evolution of the Solar System)
-
protoplanetary disk, out of which Earth and other Solar System bodies formed (from Solar System)Diagram of the early Solar System's
- The motion of 'lights' moving across the sky is the basis of the classical definition of planets: wandering stars. (from
-
Comet Hale–Bopp seen in 1997 (from Solar System)
-
Emanuel Bowen in 1747. At that time, Uranus, Neptune, nor the asteroid belts have been discovered yet. (from Solar System)True-scale Solar System poster made by
-
Triton, taken by Voyager 2. Triton's orbit will eventually take it within Neptune's Roche limit, tearing it apart and possibly forming a new ring system. (from Formation and evolution of the Solar System)Neptune and its moon
-
Hubble image ofstellar nursery probably very similar to the primordial nebula from which the Sun formed (from Formation and evolution of the Solar System)
Did you know –
- ... that Sun-centeredorbit?
- ...that the Solar Sentinels, a NASA spacecraft designed to study the Sun, will have to survive at distances from the Sun only one-quarter of Earth's distance?
- ...that just over 50 kilometres above its surface, the atmosphere of Venus has very similar pressure and temperature as does Earth, making it the most Earth-like area in the Solar System?
- ...that , or beyond?
- ...that the Caloris Basin on Mercury, one of the largest impact basins in the Solar System, is surrounded by a series of geological formations believed to have been produced by the basin's ejecta?
- ...that Kordylewski clouds are large concentrations of dust that orbit Earth at the distance of the Moon?
- ...that no viable solution has yet been found to counteract astronauts on any future mission to Mars?
- ...that Galileo mission to Jupiter?
Categories
Major categoriesSolar System Celestial mechanics Comets ...in fiction Minor planets Moons Planetary missions Planets... Sun Surface feature nomenclature...
Full category treeSelect [►] to view subcategoriesIn the news
Wikinews Space portal- April 7: NASA's helicopter Ingenuity survives its first night at Mars
- December 25: 'Earth-based life can survive in hydrogen-rich atmospheres': MIT professor Dr Seager tells Wikinews about her research on organisms thriving in oxygen-less environment
- July 7: Astronomer Anthony Boccaletti discusses observation of birth of potential exoplanet with Wikinews
- May 31: SpaceX successfully launches its first crewed spaceflight
- May 22: Astronomer tells Wikinews about discovery of closest black hole known so far
- October 12: Cosmonaut Alexei Leonov dies at age 85
- October 10: Swedish academy announces 2019 Nobel Prize winners in physics
- September 14: Astronomers find water vapour in atmosphere of exoplanet K2-18b
- March 5: SpaceX Crew Dragon capsule docks with International Space Station
- January 9: Simple animals could live in Martian brines: Wikinews interviews planetary scientist Vlada Stamenković
- November 29: NASA's InSight Lander makes it to Mars
- October 12: Manned Soyuz space mission aborts during launch
Major topics
Moons · Planetariums- Sun: Sunspot · Solar wind · Solar flare · Solar eclipse
- Mercury: Geology · Exploration (Mariner 10 · MESSENGER · BepiColombo) · Transit
- Magellan · Venus Express) · Transit
- Earth: History · Geology · Geography · Atmosphere · Rotation
- )
- Ceres: Exploration (Dawn)
- )
- Huygens)
- Uranus: Moons (Miranda · Ariel · Umbriel · Titania · Oberon) · Rings · Exploration (Voyager 2)
- Neptune: Moons (Triton) · Rings · Exploration (Voyager 2)
- Planets beyond Neptune
- Pluto: Moons (Charon, Nix, Hydra, Kerberos, Styx) · Exploration (New Horizons)
- Hi'iaka, Namaka)
- Makemake
- Eris: Dysnomia
- Centaurs · TNOs (Kuiper belt · Scattered disc · Oort cloud) · Comets (Hale–Bopp · Halley's · Hyakutake · Shoemaker–Levy 9)
- Formation and evolution of the Solar System: History of Solar System formation and evolution hypotheses · Nebular hypothesis
- See also: Good articles · List of objects
Bold articles are featured.
Italicized articles are on dwarf planets or major moons.Things you can do
Here are some tasks awaiting attention:- WikiProject Solar System and other WikiProjectsrelated to this subject
Related portals
Related WikiProjects
Solar SystemMoonMars
Astronomy Astronomical objects Spaceflight Associated Wikimedia
The following Wikimedia Foundation sister projects provide more on this subject:
-
Commons
Free media repository -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikiversity
Free learning tools -
Wiktionary
Dictionary and thesaurus
Discover Wikipedia using portals