Solar System
hideThe Solar System[a] consists of the Sun and those celestial objects bound to it by gravity, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The Sun's retinue of objects circle it in a nearly flat disc called the ecliptic plane, most of the mass of which is contained within eight relatively solitary planets whose orbits are almost circular. The four smaller inner planets; Mercury, Venus, Earth and Mars, also called the terrestrial planets, are primarily composed of rock and metal. The four outer planets, Jupiter, Saturn, Uranus and Neptune, also called the gas giants, are composed largely of hydrogen and helium and are far more massive than the terrestrials.
The Solar System is also home to two main belts of small bodies. The asteroid belt, which lies between Mars and Jupiter, is similar to the terrestrial planets as it is composed mainly of rock and metal. The Kuiper belt (and its subpopulation, the scattered disc), which lies beyond Neptune's orbit, is composed mostly of ices such as water, ammonia and methane. Within these belts, five individual objects, Ceres, Pluto, Haumea, Makemake and Eris, are recognised to be large enough to have been rounded by their own gravity, and are thus termed dwarf planets. The hypothetical Oort cloud, which acts as the source for long-period comets, may also exist at a distance roughly a thousand times beyond these regions.
Within the Solar System, various populations of small bodies, such as comets, centaurs and interplanetary dust, freely travel between these regions, while the solar wind, a flow of plasma from the Sun, creates a bubble in the interstellar medium known as the heliosphere, which extends out to the edge of the scattered disc.
Six of the planets and three of the dwarf planets are orbited by natural satellites, usually termed "moons" after Earth's Moon. Each of the outer planets is encircled by planetary rings of dust and other particles.
For more information about Solar System, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with solar
Japan eyes solar station in space as new energy source
18 hours ago |
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It may sound like a sci-fi vision, but Japan's space agency is dead serious: by 2030 it wants to collect solar power in space and zap it down to Earth, using laser beams or microwaves.
Pioneering Swiss solar-powered plane rolled out
Nov 06, 2009 |
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Solar Impulse, the Swiss bid to make the first solar-powered flight around the world, rolled out its prototype on Friday at an airbase near Zurich and powered up the engines.
Scientists Reproduce a Building Block of Life in Laboratory
Nov 06, 2009 |
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(PhysOrg.com) -- NASA scientists studying the origin of life have reproduced uracil, a key component of our hereditary material, in the laboratory.
Unusual meteorite found by time-lapse camera observatory
Space & Earth / Space Exploration
Nov 05, 2009 |
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(PhysOrg.com) -- An unusual meteorite with an interesting orbit has been tracked to the ground using a photographic observatory that records time-lapse images of fireballs traveling across the sky.
Solar power generation around the clock
Nov 05, 2009 |
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(PhysOrg.com) -- A Californian company, SolarReserve, is developing a solar power system that can store seven hours' worth of solar energy by focusing mirrors onto millions of gallons of molten salt, allowing ...
Hidden Territory on Mercury Revealed
Space & Earth / Space Exploration
Nov 04, 2009 |
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The MESSENGER spacecraft's third flyby of the planet Mercury has given scientists, for the first time, an almost complete view of the planet's surface and revealed some dramatic changes in Mercury's comet-like ...
Toward home-brewed electricity with 'personalized solar energy'
Nov 04, 2009 |
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New scientific discoveries are moving society toward the era of "personalized solar energy," in which the focus of electricity production shifts from huge central generating stations to individuals in their ...
Rosetta's final Earth boost
Space & Earth / Space Exploration
Nov 04, 2009 |
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ESA's comet chaser Rosetta will swing by Earth for the last time on 13 November to pick up energy and begin the final leg of its 10-year journey to comet 67P/Churyumov-Gerasimenko. ESA's European Space Operations ...
Will Europe Be Powered by the Sahara
Nov 04, 2009 |
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(PhysOrg.com) -- Europe has long been interested in developing alternative energy sources. And, one of the more interesting places that some Europeans are looking for solar power is the Sahara. With the vast ...
Fantastic Voyage
Space & Earth / Space Exploration
Nov 02, 2009 |
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By travelling to the outer solar system, the two Voyager spacecraft allowed us to see amazing details of far-distant planets and moons.
'Ultra-primitive' particles found in comet dust
Space & Earth / Space Exploration
Nov 02, 2009 |
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Dust samples collected by high-flying aircraft in the upper atmosphere have yielded an unexpectedly rich trove of relicts from the ancient cosmos, report scientists from the Carnegie Institution. The stratospheric ...
3-D system based on optical fiber could provide new options for photovoltaics
Nanotechnology / Nanomaterials
Nov 02, 2009 |
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Converting sunlight to electricity might no longer mean large panels of photovoltaic cells atop flat surfaces like roofs.
Danish nanowires have great potential
Nov 02, 2009 |
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Danish nanophysicists have developed a new method for manufacturing the cornerstone of nanotechnology research - nanowires. The discovery has great potential for the development of nanoelectronics and highly ...
Solar winds triggered by magnetic fields
Nov 02, 2009 |
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(PhysOrg.com) -- Solar wind generated by the sun is probably driven by a process involving powerful magnetic fields, according to a new study led by UCL (University College London) researchers based on the ...
Porphyrin Dimers Increase Efficiency of Dye-Sensitized Solar Cells
Oct 30, 2009 |
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(PhysOrg.com) -- Porphyrins are most commonly thought of as the pigment in red blood cells, but now scientists have found that porphyrins can also be used to increase the efficiency of an inexpensive type ...
