Business

Analysis identifies drivers of offshore wind development

As much as 20% of regional power needs along the Atlantic coast could be served by offshore wind farms by 2050, according to researchers with the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) who ...

Engineering

Solar cell material can assist self-driving cars in the dark

Material used in organic solar cells can also be used as light sensors in electronics. This has been shown by researchers at Linköping University, Sweden, who have developed a type of sensor able to detect circularly polarized ...

Energy & Green Tech

Nanofluidic device generates power with saltwater

There is a largely untapped energy source along the world's coastlines: the difference in salinity between seawater and freshwater. A new nanodevice can harness this difference to generate power.

Business

Predicting the sustainability of a future hydrogen economy

As renewable energy sources like wind and solar ramp up, they can be used to sustainably generate hydrogen fuel. But implementing such a strategy on a large scale requires land and water dedicated to this purpose.

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Solar System

The 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.

This text uses material from Wikipedia, licensed under CC BY-SA