magnetosphere

Cassini-Huygens is a joint NASA/ESA/ASI unmanned space mission intended to study Saturn and its moons. The spacecraft consists of two main elements: the Cassini orbiter, named after the Italian-French astronomer Giovanni Domenico Cassini, and the Huygens probe, named after the Dutch astronomer Christiaan Huygens. It was launched on October 15, 1997 and entered Saturn's orbit on July 1, 2004. On December 25, 2004 the probe separated from the orbiter at approximately 02:00 UTC, with deployment confirmed by th ...

Including:

• Cassini-Huygens - Overview
• Cassini-Huygens - History
• Cassini-Huygens - Spacecraft design
• Cassini-Huygens - Instrumentation
• Cassini-Huygens - Plutonium power source and controversy
• Cassini-Huygens - The Huygens probe
• Cassini-Huygens - Important events and discoveries
• Cassini-Huygens - Timeline
• Cassini-Huygens - Jupiter flyby
• Cassini-Huygens - Test of Einstein's theory of general relativity
• Cassini-Huygens - Spoke phenomenon verified
• Cassini-Huygens - New moons of Saturn
• Cassini-Huygens - Phoebe flyby
• Cassini-Huygens - Saturn rotation
• Cassini-Huygens - Orbiting Saturn
• Cassini-Huygens - Titan flybys
• Cassini-Huygens - Huygens encounter with Titan
• Cassini-Huygens - Enceladus flybys
• Cassini-Huygens - Radio Occultations of Saturn's Rings
• Cassini-Huygens - Trajectory
• Cassini-Huygens - Notes
• Cassini-Huygens - Books and print references

Read more here: » Cassini-Huygens: Encyclopedia - Cassini-Huygens

In the solar system, the composition of the solar wind is identical to the Sun's corona: 73% ionized hydrogen and 25% ionized helium with the remainder as trace impurities. These components are present as a plasma, consisting of about 95% singly ionized hydrogen, 4% doubly ionized helium, and less than 0.5% other ions (often called minor ions). The exact composition has been difficult to measure due to large fluctuations. A sample return mission, Genesis, returned to Earth in 2004 and is undergoing analysis, but it was damaged by crash-landing when its parachute failed to deploy on re-entry to Earth's atmosphere, ...

See also:

Solar wind, Solar wind - History, Solar wind - Properties, Solar wind - Fast and slow solar wind, Solar wind - Variability and space weather, Solar wind - Outer limits, Solar wind - Notes

Read more here: » Solar wind: Encyclopedia II - Solar wind - Properties

The satellite constellation researches the protective magnetosphere of the Earth that shields us from the continual solar wind. Cluster FM5 to FM8 (FM1 to FM4 were lost in the 1996 failed launch) measure three dimensional data from the collision of the solar wind with the Earth's magnetic field, its changes over time and the resulting effects on near-Earth space and its atmosphere including aurorae and even electrical outages. One goal of the mission was to improve ...

See also:

Cluster mission, Cluster mission - Mission overview - 4 satellites 4-dimensional, Cluster mission - Launches in 2000 July and August, Cluster mission - Constellation at the end of 2003, Cluster mission - Chinese Double Star 2003, Cluster mission - Partial list of discoveries, Cluster mission - 2002

Read more here: » Cluster mission: Encyclopedia II - Cluster mission - Mission overview - 4 satellites 4-dimensional

Astra Alan Davis, artist Astra is a fictional character, a supervillain in the Marvel Comics universe. She first appeared in Uncanny X-Men #366 and was created by Alan Davis. She is a mutant teleporter who was revealed to be Magneto's first true recruit from his original Brotherhood of Evil Mutants. With her aid, he would acquire technology from alien civilizations, which would automatically give him advantage over the contemporary human military forces. However, she did not share Magneto’s goals - merely wanti ...

Read more here: » Astra comics: Encyclopedia - Astra comics

Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly 78% nitrogen and 21% oxygen, with trace amounts of other gases. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night. The atmosphere has no abrupt cut-off. It slowly becomes thinner and fades away into space. There is no definite boundary between the atmosphere and outer space. Three-quarters of the atmosphere's mass is with ...

Including:

• Earth's atmosphere - Temperature and the atmospheric layers
• Earth's atmosphere - Various atmospheric regions
• Earth's atmosphere - Pressure
• Earth's atmosphere - Thickness of the atmosphere
• Earth's atmosphere - Composition
• Earth's atmosphere - Heterosphere
• Earth's atmosphere - Density and mass
• Earth's atmosphere - The evolution of the Earth's atmosphere

Read more here: » Earth's atmosphere: Encyclopedia - Earth's atmosphere

A satellite is any object that orbits another object (which is known as its primary). All masses that are part of the solar system, including the Earth, are satellites either of the Sun, or satellites of those objects, such as the Moon. It is not always a simple matter to decide which is the 'satellite' in a pair of bodies. Because all objects exert gravity, the motion of the primary object is also affected by the satellite. If two objects are sufficiently similar in mass, they are generally referred to as a binary syste ...

Including:

• Satellite - Artificial satellites
• Satellite - History of artificial satellites
• Satellite - Types of satellites
• Satellite - Orbit types
• Satellite - Countries with satellite launch capability
• Satellite - Reference

Read more here: » Satellite: Encyclopedia - Satellite

In common usage, an image (from Latin imago) or picture is an artifact that reproduces the likeness of some subject—usually a physical object or a person. Images may be two dimensional, such as a photograph, or three dimensional such as in a statue. They are typically produced by optical devices—such as a cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces. The word image' is also used in the broader sense of any two-d ...

Including:

• Image - Specialised meanings

Read more here: » Image: Encyclopedia - Image

The North Pole is the northernmost point on any planet. There are various ways of defining a planet's North Pole. Earth's North Pole, however it is defined, lies in the Arctic Ocean. North Pole - Defining the North Pole of Earth. The North Pole, the northernmost point on the Earth, can be defined in four different ways. Only the first two definitions are commonly used. However it is defined, the North Pole lies in the Arctic Ocean. The Geographic North Pole, also known as True ...

Including:

• North Pole - Defining the North Pole of Earth
• North Pole - Geographic North Pole
• North Pole - Expeditions
• North Pole - Magnetic North
• North Pole - Geomagnetic North Pole
• North Pole - Northern Pole of Inaccessibility
• North Pole - Defining North Poles in astronomy
• North Pole - Day and night
• North Pole - Territorial claims to the North Pole Arctic
• North Pole - Magnetic declination
• North Pole - Cultural references to the North Pole

Read more here: » North Pole: Encyclopedia - North Pole

Saturn is the sixth planet from the Sun. It is a gas giant, the second-largest planet in the solar system after Jupiter. Saturn has a prominent system of rings, consisting of mostly ice particles with a smaller amount of rocky debris. It was named after the Roman god Saturn. Its symbol is a stylized representation of the god's sickle (Unicode: ♄). The Chinese, Korean, Japanese, and Vietnamese cultures refer to the planet as the earth star (土星), based on the Five Elements. [2], [3] Including:

• Saturn - Physical characteristics
• Saturn - Rotational behavior
• Saturn - Planetary rings
• Saturn - History
• Saturn - Physical characteristics
• Saturn - Dark side of the rings
• Saturn - Spokes of the rings
• Saturn - Natural satellites
• Saturn - Exploration of Saturn
• Saturn - Pioneer 11 flyby
• Saturn - Voyager flybys
• Saturn - Cassini orbiter
• Saturn - Best viewing of Saturn
• Saturn - Appearance
• Saturn - Occultation of stars by Saturn between 1800 and 2100
• Saturn - Saturn in fiction and film
• Saturn - Saturn in various cultures

Read more here: » Saturn: Encyclopedia - Saturn

The polar aurora is a glow observed in the night sky in the polar zone. It is also known as "northern lights" or "aurora borealis," Latin for "northern dawn" since (in Europe especially) it often appears as a reddish glow on the northern horizon, as if the sun were rising from an unusual direction. Aurora borealis most often occurs from September to October and March to April. Its southern counterpart "aurora australis," has identical properties, so scientists prefer "polar au ...

Including:

• Aurora astronomy - Auroral forms and magnetism
• Aurora astronomy - The solar wind and magnetosphere
• Aurora astronomy - The origin of the aurora
• Aurora astronomy - Sources and types of aurora
• Aurora astronomy - Auroras on other planets
• Aurora astronomy - Obsolete theories
• Aurora astronomy - Aurora in folklore
• Aurora astronomy - References

Read more here: » Aurora astronomy: Encyclopedia - Aurora astronomy

Jupiter is the fifth planet from the Sun and by far the largest within our solar system. Some have described the solar system as consisting of the Sun, Jupiter, and assorted debris,[2]; some describe Jupiter as the solar system's vacuum cleaner, due to its immense gravity well. It and the other gas giants - Saturn, Uranus, and Neptune, are sometimes referred to as "Jovian planets." The Romans named the planet after the Roman god Jupiter (also called Jove). The astronomical symbol for the planet is a styliz ...

Including:

• Jupiter - Overview
• Jupiter - Physical characteristics
• Jupiter - Planetary composition
• Jupiter - Atmosphere
• Jupiter - Planetary rings
• Jupiter - Magnetosphere
• Jupiter - Appearance
• Jupiter - Exploration of Jupiter
• Jupiter - Pioneer flyby missions
• Jupiter - Voyager flyby missions
• Jupiter - Ulysses flyby mission
• Jupiter - Galileo mission
• Jupiter - Cassini flyby mission
• Jupiter - Future probes
• Jupiter - Natural satellites
• Jupiter - Galilean moons
• Jupiter - Classification of Jupiter's moons
• Jupiter - Life on Jupiter
• Jupiter - Trojan asteroids
• Jupiter - Cometary impact
• Jupiter - Jupiter in fiction and film
• Jupiter - Jupiter and Internet conspiracists

Read more here: » Jupiter: Encyclopedia - Jupiter

In 1916, Norwegian researcher Kristian Birkeland was probably the first person to successfully predict that in the Solar Wind, "From a physical point of view it is most probable that solar rays are neither exclusively negative nor positive rays, but of both kinds"; in other words, the Solar Wind consists of both negative electrons and positive ions. ^{See also:}

Solar wind, Solar wind - History, Solar wind - Properties, Solar wind - Fast and slow solar wind, Solar wind - Variability and space weather, Solar wind - Outer limits, Solar wind - Notes

Read more here: » Solar wind: Encyclopedia II - Solar wind - History

The Cluster mission is an European Space Agency (ESA) unmanned space mission mission to study the Earth's magnetosphere using four identical spacecraft flying in a tetrahedral formation. The first four Cluster spacecraft were lost in the Ariane 5 flight failure on 1996 June 4, leading to the rebuilding of four new spacecraft and their successful launching in 2000 on Soyuz-Fregat rockets. Cluster mission - Mission overview - 4 satellites 4-dimensional. The satellite constellation researches the protective ma ...

Including:

• Cluster mission - Mission overview - 4 satellites 4-dimensional
• Cluster mission - Launches in 2000 July and August
• Cluster mission - Constellation at the end of 2003
• Cluster mission - Chinese Double Star 2003
• Cluster mission - Partial list of discoveries
• Cluster mission - 2002

Read more here: » Cluster mission: Encyclopedia - Cluster mission

Some of the moons of the outer planets of the solar system are large enough to be suitable places for colonization. Many of the larger moons contain water ice, liquid water, and organic compounds that might be useful for rocket fuel production among other things. Colonies in the outer solar system could also serve as centres for long term investigation of the planet and the other moons. In particular, robotic devices could be controlled by humans without the very long time delays needed to communicate with Earth. There have also been proposa ...

Including:

• Colonization of the outer solar system - Asteroids
• Colonization of the outer solar system - Ceres
• Colonization of the outer solar system - Jupiter
• Colonization of the outer solar system - Europa
• Colonization of the outer solar system - Ganymede
• Colonization of the outer solar system - Callisto
• Colonization of the outer solar system - Saturn
• Colonization of the outer solar system - Titan
• Colonization of the outer solar system - Uranus
• Colonization of the outer solar system - Neptune
• Colonization of the outer solar system - Kuiper Belt and Oort Cloud

Read more here: » Colonization of the outer solar system: Encyclopedia - Colonization of the outer solar system

A coronal mass ejection (CME) is a solar event which involves a burst of plasma consisting primarily of electrons and protons (in addition to small quantities of heavier elements such as helium, oxygen, and iron). When these CMEs reach the Earth, they often disrupt the Earth's magnetosphere, compressing it on the dayside and extending the nightside tail. When the magnetosphere reconnects on the nightside, it creates trillions of watts of power which is directed back towards the Earth's upper atmosphere. This process can cause particul ...

Read more here: » Coronal mass ejection: Encyclopedia - Coronal mass ejection

The Van Allen radiation belt is a torus of energetic charged particles (ie. a plasma) around Earth, trapped by Earth's magnetic field. When the belts "overload", particles strike the upper atmosphere and fluoresce, causing the polar aurora. The presence of a radiation belt had been theorized prior to the Space Age and the belt's presence was confirmed by the Explorer I on January 31, 1958 and Explorer III missions, under Doctor James Van Allen. The trapped ...

Including:

• Van Allen radiation belt - The Outer Van Allen Belt
• Van Allen radiation belt - The Van Allen Belt's impact on space travel
• Van Allen radiation belt - The Van Allen Belts and why they exist
• Van Allen radiation belt - Removing the belts
• Van Allen radiation belt - Trivia

Read more here: » Van Allen radiation belt: Encyclopedia - Van Allen radiation belt

1958 (MCMLVIII) was a common year starting on Wednesday of the Gregorian calendar. 1958 - Events. 1958 - January. January 1 - Treaty of Rome founding the EU is implemented. January 3 - The West Indies Federation is formed. January 4 - Sputnik 1 falls to Earth from its orbit (launched on October 4, 1957). January 8 - 14 year old Bobby Fischer wins the United States Chess Championship. January 13 - 9235 scientists publish a plea to ...

Including:

• 1958 - Events
• 1958 - January
• 1958 - February
• 1958 - March
• 1958 - April
• 1958 - May
• 1958 - June
• 1958 - July
• 1958 - August
• 1958 - September
• 1958 - October
• 1958 - November
• 1958 - December
• 1958 - unknown date
• 1958 - Births
• 1958 - January
• 1958 - February
• 1958 - March
• 1958 - April
• 1958 - May
• 1958 - June
• 1958 - July
• 1958 - August
• 1958 - September-December
• 1958 - Deaths
• 1958 - Nobel Prizes
• 1958 - Fields Medalists

Read more here: » 1958: Encyclopedia - 1958

Comet Shoemaker-Levy 9 (SL9, formally designated D/1993 F2) was a comet which collided with Jupiter in 1994, providing the first direct observation of the collision of two solar system objects. This generated a large amount of coverage in the popular media, and SL9 was closely observed by astronomers worldwide. The comet provided many revelations about Jupiter and its atmosphere and highlighted Jupit ...

Including:

• Comet Shoemaker-Levy 9 - Discovery
• Comet Shoemaker-Levy 9 - A Jupiter-orbiting comet
• Comet Shoemaker-Levy 9 - Predictions for the collision
• Comet Shoemaker-Levy 9 - Impacts
• Comet Shoemaker-Levy 9 - Observations and discoveries
• Comet Shoemaker-Levy 9 - Chemical studies
• Comet Shoemaker-Levy 9 - Seismic waves
• Comet Shoemaker-Levy 9 - Other observations
• Comet Shoemaker-Levy 9 - Post-impact analysis
• Comet Shoemaker-Levy 9 - Longer term effects
• Comet Shoemaker-Levy 9 - Frequency of impacts
• Comet Shoemaker-Levy 9 - Jupiter as a cosmic vacuum cleaner

Read more here: » Comet Shoemaker-Levy 9: Encyclopedia - Comet Shoemaker-Levy 9

In a planetary magnetosphere, the bow shock is the boundary at which the solar wind abruptly drops as a result of its approach to the magnetopause. The most well-studied example of a bow shock is when the solar wind encounters the Earth's magnetopause, although bow shocks occur around all planets. The Earth's bow shock is about 100-1000 km thick and located about 90,000 km from the Earth. The defining criterion is that the bulk velocity of the fluid (in this case, the solar wind) drops from "supersonic" to "subsonic", where the speed ...

Read more here: » Bow shock: Encyclopedia - Bow shock

A Birkeland current generally refers to any electric current in a space plasma, but more specifically when charged particles in the current follow magnetic field lines. They are caused by the movement of a plasma perpendicular to a magnetic field. Birkeland currents often show filamentary, or twisted "rope-like" magnetic structure. They are sometimes referred to as field-aligned currents. Originally Birkeland currents referred to electric currents that contribute to the aurora, caused by the interaction of the pla ...

Including:

• Birkeland current - Characteristics
• Birkeland current - Cosmic Birkeland currents
• Birkeland current - History
• Birkeland current - Web site links

Read more here: » Birkeland current: Encyclopedia - Birkeland current