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
NJIT receives funding to improve Big Bear Telescope, study solar energy
Nov 20, 2009 |
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NJIT researchers are at work on many scientific and technological frontiers. The National Science Foundation has recently provided support that totals nearly $4.3 million for the diverse efforts of the following ...
SOFIA Seeks Secrets of Planetary Birth
Space & Earth / Space Exploration
Nov 19, 2009 |
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You don't always have to have a rocket to do rocket science. Sometimes a mere airplane will do - that is, a mere Boeing 747 toting a 17-ton, 9-foot wide telescope named SOFIA.
Mystery of the Solar Tsunami -- Solved (w/ Video)
Nov 19, 2009 |
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(PhysOrg.com) -- Sometimes you really can believe your eyes. That's what NASA's Solar Terrestrial Relations Observatory (STEREO) is telling researchers about a controversial phenomenon on the sun known as ...
Experts: Failure to focus on farming will undermine global climate agreement and increase hunger
Nov 18, 2009 |
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Alarmed by a substantial oversight in the global climate talks leading up to the United Nations Climate Change Conference in Copenhagen next month, more than 60 of the world's most prominent agricultural scientists and leaders ...
Dawn Enters Asteroid Belt -- For Good
Space & Earth / Space Exploration
Nov 16, 2009 |
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(PhysOrg.com) -- NASA's Dawn spacecraft re-entered our solar system's asteroid belt today, Nov. 13, and this time it will stay there.
Measuring Electron Orbitals
Nov 16, 2009 |
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(PhysOrg.com) -- For the first time, it has been possible to measure electron density in individual molecular states using what is known as the photoelectric effect. Now published in Science, this method repres ...
The Future in Two Words: Ionic Liquids
Nov 13, 2009 |
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(PhysOrg.com) -- Ionic liquids are molecular solutions that have a wide range of potential applications, including next-generation solar cells, hydrogen fuel cells and lithium batteries.
LCROSS Impact Finds Water on the Moon
Space & Earth / Space Exploration
Nov 13, 2009 |
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(PhysOrg.com) -- The argument that the moon is a dry, desolate place no longer holds water. Secrets the moon has been holding, for perhaps billions of years, are now being revealed to the delight of scientists ...
Research gives new insights into 4 billion year-old meteorites
Nov 12, 2009 |
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(PhysOrg.com) -- Scientists have gained new insight into the makeup of ancient meteorites called Carbonaceous Chondrites, in research published in the October edition of the journal Earth Science and Planetary Le ...
A faraway planet intrigues: Exoplanet with extremely tilted orbit raises new interest in stellar astronomy
Nov 12, 2009 |
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(PhysOrg.com) -- Two teams of astronomers have found a planet outside the solar system that might be orbiting backwards compared to its star's rotation, a discovery that could shed light on how unique the ...
A Tale of Planetary Woe (w/ Video)
Space & Earth / Space Exploration
Nov 11, 2009 |
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Once upon a time — roughly four billion years ago — Mars was warm and wet, much like Earth. Liquid water flowed on the Martian surface in long rivers that emptied into shallow seas. A thick atmosphere blanketed ...
A lightning strike in Africa helps take the pulse of the sun
Space & Earth / Space Exploration
Nov 11, 2009 |
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Sunspots, which rotate around the sun's surface, tell us a great deal about our own planet. Scientists rely on them, for instance, to measure the sun's rotation or to prepare long-range forecasts of the Earth's ...
A bubbling ball of gas (w/ Video)
Space & Earth / Space Exploration
Nov 11, 2009 |
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The Sun is a bubbling mass. Packages of gas rise and sink, lending the sun its grainy surface structure, its granulation. Dark spots appear and disappear, clouds of matter dart up - and behind the whole thing ...
Atomic Particles Help Solve Planetary Puzzle
Space & Earth / Earth Sciences
Nov 10, 2009 |
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(PhysOrg.com) -- A University of Arkansas professor and his colleagues have shown that the Earth's mantle contains the same isotopic signatures from magnesium as meteorites do, suggesting that the planet formed ...
The 2009 Leonid Meteor Shower
Space & Earth / Space Exploration
Nov 10, 2009 |
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This year's Leonid meteor shower peaks on Tuesday, Nov. 17th. If forecasters are correct, the shower should produce a mild but pretty sprinkling of meteors over North America followed by a more intense outburst ...
