28nm bitcoin mining cards of humanity clip, save and share what you find with family and friends. Easily download and save what you find. Jump to navigation Jump to search This article is about the Sun and its planetary system.
The Solar System is the gravitationally bound system of the planets and the Sun plus other objects that orbit it, either directly or indirectly. 6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The Solar System also contains smaller objects. The asteroid belt, which lies between the orbits of Mars and Jupiter, mostly contains objects composed, like the terrestrial planets, of rock and metal.
The solar wind, a stream of charged particles flowing outwards from the Sun, creates a bubble-like region in the interstellar medium known as the heliosphere. For most of history, humanity did not recognize or understand the concept of the Solar System. Renaissance believed Earth to be stationary at the centre of the universe and categorically different from the divine or ethereal objects that moved through the sky. The principal component of the Solar System is the Sun, a G2 main-sequence star that contains 99. Most large objects in orbit around the Sun lie near the plane of Earth’s orbit, known as the ecliptic. The planets are very close to the ecliptic, whereas comets and Kuiper belt objects are frequently at significantly greater angles to it. The overall structure of the charted regions of the Solar System consists of the Sun, four relatively small inner planets surrounded by a belt of mostly rocky asteroids, and four giant planets surrounded by the Kuiper belt of mostly icy objects.
Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars and Mercury. All planets of the Solar System lie very close to the ecliptic. Kepler’s laws of planetary motion describe the orbits of objects about the Sun.
Following Kepler’s laws, each object travels along an ellipse with the Sun at one focus. Jupiter and Saturn, which comprise nearly all the remaining matter, are also primarily composed of hydrogen and helium. For comparison, the radius of the Sun is 0. With a few exceptions, the farther a planet or belt is from the Sun, the larger the distance between its orbit and the orbit of the next nearer object to the Sun.
For example, Venus is approximately 0. 33 AU farther out from the Sun than Mercury, whereas Saturn is 4. 3 AU out from Jupiter, and Neptune lies 10. Some Solar System models attempt to convey the relative scales involved in the Solar System on human terms. Distances are to scale, objects are not.
Distances of selected bodies of the Solar System from the Sun. The left and right edges of each bar correspond to the perihelion and aphelion of the body, respectively, hence long bars denote high orbital eccentricity. The radius of the Sun is 0. 568 billion years ago from the gravitational collapse of a region within a large molecular cloud. This initial cloud was likely several light-years across and probably birthed several stars. Due to their higher boiling points, only metals and silicates could exist in solid form in the warm inner Solar System close to the Sun, and these would eventually form the rocky planets of Mercury, Venus, Earth, and Mars. Because metallic elements only comprised a very small fraction of the solar nebula, the terrestrial planets could not grow very large.
Within 50 million years, the pressure and density of hydrogen in the centre of the protostar became great enough for it to begin thermonuclear fusion. The Solar System will remain roughly as we know it today until the hydrogen in the core of the Sun has been entirely converted to helium, which will occur roughly 5 billion years from now. This will mark the end of the Sun’s main-sequence life. At this time, the core of the Sun will contract with hydrogen fusion occurring along a shell surrounding the inert helium, and the energy output will be much greater than at present.
The Sun is the Solar System’s star and by far its most massive component. The Sun is a G2-type main-sequence star. Hotter main-sequence stars are more luminous. The Sun’s temperature is intermediate between that of the hottest stars and that of the coolest stars. The vast majority of the Solar System consists of a near-vacuum known as the interplanetary medium.