Jupiter (pronounced /ˈdʒuːpɨtɚ/ (help·info)^[9]) is the fifth planet from the Sun and the largest planet within the Solar System.^[10] It is two and a half times as massive as all of the other planets in our Solar System combined. Jupiter is classified as a gas giant, along with Saturn, Uranus and Neptune. Together, these four planets are sometimes referred to as the Jovian planets.

The planet was known by astronomers of ancient times and was associated with the mythology and religious beliefs of many cultures. The Romans named the planet after the Roman god Jupiter.^[11] When viewed from Earth, Jupiter can reach an apparent magnitude of −2.8, making it the third brightest object in the night sky after the Moon and Venus. (However, at certain points in its orbit, Mars can briefly exceed Jupiter's brightness.)

The planet Jupiter is primarily composed of hydrogen with a small proportion of helium; it may also have a rocky core of heavier elements under high pressure. Because of its rapid rotation, Jupiter's shape is that of an oblate spheroid (it possesses a slight but noticeable bulge around the equator). The outer atmosphere is visibly segregated into several bands at different latitudes, resulting in turbulence and storms along their interacting boundaries. A prominent result is the Great Red Spot, a giant storm that is known to have existed since at least the 17th century. Surrounding the planet is a faint planetary ring system and a powerful magnetosphere. There are also at least 63 moons, including the four large moons called the Galilean moons that were first discovered by Galileo Galilei in 1610. Ganymede, the largest of these moons, has a diameter greater than that of the planet Mercury.

Jupiter has been explored on several occasions by robotic spacecraft, most notably during the early Pioneer and Voyager flyby missions and later by the Galileo orbiter. The latest probe to visit Jupiter was the Pluto-bound New Horizons spacecraft in late February 2007. The probe used the gravity from Jupiter to increase its speed and adjust its trajectory toward Pluto, thereby saving years of travel. Future targets for exploration include the possible ice-covered liquid ocean on the Jovian moon Europa.

Contents [hide] 1 Structure 1.1 Composition 1.2 Mass 1.3 Internal structure 1.4 Cloud layers 1.5 Great Red Spot and other storms 1.6 Planetary rings 1.7 Magnetosphere 2 Orbit and rotation 3 Observation 4 Research and exploration 4.1 Ground-based telescope research 4.2 Exploration with space probes 4.2.1 Flyby missions 4.2.2 Galileo mission 4.2.3 Future probes 5 Moons 5.1 Galilean moons 5.2 Classification of moons 6 Interaction with the Solar System 7 Possibility of life 8 Human culture 9 See also 10 References 11 Further reading 12 External links

Structure

Jupiter is one of the four gas giants; that is, it is not primarily composed of solid matter. It is the largest planet in the Solar System, having a diameter of 142,984 km at its equator. Jupiter's density, 1.326 g/cm³, is the second highest of the gas giant planets, but lower than any of the four terrestrial planets.

Composition

Jupiter's upper atmosphere is composed of about 88-92% hydrogen and 8-12% helium by percent volume or fraction of gas molecules (see table to the right). Since a helium atom has about four times as much mass as a hydrogen atom, the composition changes when described in terms of the proportion of mass contributed by different atoms. Thus the atmosphere is approximately 75% hydrogen and 24% helium by mass, with the remaining one percent of the mass consisting of other elements. The interior contains denser materials such that the distribution is roughly 71% hydrogen, 24% helium and five percent other elements by mass. The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. The outermost layer of the atmosphere contains crystals of frozen ammonia.^[12][13] Through infrared and ultraviolet measurements, trace amounts of benzene and other hydrocarbons have also been found.^[14]

The atmospheric proportions of hydrogen and helium are very close to the theoretical composition of the primordial solar nebula. However, neon in the upper atmosphere only consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun.^[15] Helium is also depleted, although to a lesser degree. This depletion may be a result of precipitation of these elements into the interior of the planet.^[16] Abundances of heavier inert gases in Jupiter's atmosphere are about two to three times that of the sun.

Based on spectroscopy, Saturn is thought to be similar in composition to Jupiter, but the other gas giants Uranus and Neptune have relatively much less hydrogen and helium.^[17] However, because of the lack of atmospheric entry probes, high quality abundance numbers of the heavier elements are lacking for the outer planets beyond Jupiter.

Mass

Approximate size comparison of Earth and Jupiter, including the Great Red Spot

Jupiter is 2.5 times more massive than all the other planets in our Solar System combined — this is so massive that its barycenter with the Sun actually lies above the Sun's surface (1.068 solar radii from the Sun'

Vuzix iWear

Компанијата Vuzix го пушти во продажба долго најавуваниот преносен видео плеер iWear кој се носи како наочари.

Во изминативе години се изнагледавме слични направи, но ниедна од нив не стана хит (иако никој од индустријата тоа не сака да го признае) бидејќи од ваквите гаџети ќе ве здоболи глава по час или два.

Vuzix iWear носи неколку новитети кои би требало да ги исправат грешките на сличните направи: прикажува виртуелен петнаесетметарски дисплеј кој вашите очи го перцепираат на растојание од 274 сантиметри, а за секое око можете да подесувате диоптрија од +2 до -5.

Батеријата трае 5,5 часа, што би требало да е доволно да се убие досадата и на прекуокеански лет.

Уредот е достапен на страницата на производителот за 249,95 долари.